Robert E. Lee, of the Confederate States of America, was beloved by his soldiers, who nicknamed him "Marse Bob" or "Marse Robert". ("Marse" was an old dialect word for "Mister" or "Master".)
William Tecumseh Sherman, of the United States, was known to his troops as "Uncle Billy," although he was known to the people of Georgia by much less printable names.
George B. McClellan was not just this trope, he was a real-life Deconstruction. On the one hand, he was a brilliant organizer, who could shape and train a disorganized mob into a formidable army; on the other hand, he was unwilling to risk his men in battle (and constantly convinced that he was outnumbered by the Confederates; if he had been, his timidity would have made perfect sense.) Lincoln's opinion of him reflected this; e once said of McClellan, "There is no man in the Army who can man these fortifications and lick these troops of ours into shape half as well as he. If he can't fight himself, he excels in making others ready to fight," but he also once said of him, "If General McClellan does not want to use the army, I would like to borrow it for a time." When he made the borrowing, replacing McClellan with Pope, the result was the disastrous Second Battle of Bull Run and McClellan being reinstated to rebuild the Army of the Potomac. (McClellan would later run for President as a Democrat, in 1864; but he lost overwhelmingly, including among his own soldiers, to Lincoln.)
There were a few notable examples from the Wehrmacht.
Erwin Rommel is regarded as having been a humane and professional officer. His Afrika Korps was never accused of war crimes, and soldiers captured during his Africa campaign were reported to have been treated humanely. Orders to kill Jewish soldiers, civilians and captured commandos were ignored.
And in that same vein, Generalfeldmarschall Albert Kesselring, nicknamed "Uncle Albert" by his troops.
Still in the same vein, General der Fallschirmtruppe Hermann-Bernhard Ramcke. His men actually acclaimed him, when he took his leave, calling him "Vater Ramcke" (Father Ramcke).
And still in the same vein, Generaloberst Hermann "Papa" Hoth.
Steiner. Yes, that Steiner who is famous because of Hitler Rants. He refused the order to launch an attack to throw the Soviets away fom Berlin because he could not get enough men, so he opted to avoid causing unnecessary deaths. He was tried for war crimes at Nuremburg. However, he was exhonorated for all of them by testimony given by his former soldiers.
General Helmuth von Pannwitz, who led Cossack volunteers in German service against their former country, was much admired among his men for, among other things, respecting their Russian customs, language, and traditions, being called, among other things, Batka (which I'm told means "father.") Fittingly, after Germany's defeat, he refused to be treated as a German POW by the Soviets and instead chose to be tried and executed with other Russian "turncoats" he led.
Generalfeldmaschall Erich von Manstein was considered one of these, as well as a Memetic Badass to the men under him. Indeed, one reason the troops in Stalingrad fought on for so long was because, when they were surrounded, he sent them a telegram reading: "Hold on. I'm going to hack you out there. Manstein." He would have too, if Hitler had let Paulus break out towards his relief effort (which was headed by General Hermann "Papa" Hoth, another example).
General Heinz Guderian, inventor of blitzkrieg, willingly fought in person on the front lines to get a sense of conditions, arguing furiously with Hitler to ensure his men's welfare, and at one point manned the machine gun of his command vehicle and blasted his way through a Polish roadblock that his men were unable to clear. Like his personal friend and fellow blitzkrieg-inventor, Erich von Manstein, he ignored orders to kill commissars on capture and ignore war crimes committed by his soldiers in Russia; but his behavior in Poland was more shady, with his soldiers looting in Brest-Litovsk. After the war, the Poles and Russians wanted him hanged for war crimes, but he was acquitted on all charges by the Nuremberg Tribunals and went on to act as a consultant of sorts for the revived West German army.
Blucher (*WHINNY*)actually called his men "my children" and was called "Father Blucher" by them. The historian David Howarth says that he was able to behave like that largely because he was so old while a younger general would have had to be more distant.
In your actual German he was called "Papa Blücher", and the younger general Howarth was thinking of was The Duke of Wellington, who was a lot more formal and stand-offish towards his soldiers.
Although that said, Wellington was A Father to His Men in his own way - a cold, "Well Done, Son" Guy way. It is noted that the Army of the Peninsula fought so hard simply because they wanted Wellington to give them a sign of his grudging approval. He gave them it too. He wept when he surveyed the carnage at the Siege of Badajoz, both because of the way his men had died but also because they let him down by brutally sacking the city afterwards. He also once cashiered a group of wealthy officers on the spot for billeting themselves in a warm house when the wounded were left outside. When the Army looted the French baggage park at Vitoria (which included pretty much the entire Treasury of the Spanish Empire), he said his famous line (which people have used so often to bash him): "Our army is the scum of the earth, the merest scum of the earth..." But people always forget/ignore the second part: "...but what fine fellows we have made of them!"
Alexander Suvorov, the best military commander in the history of Russia and one of the few undefeated commanders in world history. The guy camped out with his soldiers even after he became a Field Marshal to stay aware of their morale and motivate them.
Leonidas, in the same vein. It has been said that he had a nickname for every Spartan at Thermopylae, and that he refused to sleep in the only tent, preferring to sleep in the mud with the men.
Colonel Robert Gould Shaw was beloved by his African-American Civil War regiment. Probably because he treated them with more respect than many of them ever knew in their lives.
General Sir John Monash, in WWI. He continually promoted the concept that a commander's role is to, above all else, ensure the safety and well-being of their subordinates. Notably, after the Battle of Hamel, where his leadership led to a 92-minute victory in conditions which would have otherwise taken months, his men remarked that the most extraordinary thing about the battle was not the tactics, the weapons or the incredible success of the operation, but the fact that Monash had hot meals delivered to the troops whilst the battle was ongoing.
General (later Field Marshal) Sir Herbert Plumer, Britain, World War One—men used to fight to be sent to his command, and few other generals of any army on either side took better care of their soldiers. Most of his attacks worked. The few that didn't were drowned in mud at Passchendaele. At the start of an attack, he would sometimes be found on his knees in prayer in his quarters, pleading to God for the safety of his men. In tears. And that was when victory was certain...
Speaking of World War I, Paul Emil von Lettow-Vorbeck, a Blue Blood Prussian general who led two thousand black African troops in perhaps the most successful guerilla campaign ever, driving the British and Portuguese out of Deutsch-Ostafrika and even ''invading'' enemy territory while hopelessly outnumbered. He appointed black officers (unheard of in a colonial European army, although it wasn't as if he had any hope of getting new German ones) and learned to speak their language fluently ("We are all Africans here.") Forced to cut rations as the British wore him down, most of his men stayed loyal and fought on rather than desert. After the war, he gave his men signed certificates so they could secure their back-pay from the ruined Imperial German government. By the time they were finally payed in 1964, many of them had lost said certificates but were able to prove their identity by performing the German Manual of Arms, which they still remembered thanks to his strict drill and discipline.
Also in World War 1, Lieutenant Siegfried Sassoon, was known for two things, besides being a great war poet: 1) being a brave, charismatic leader whose troops were devoted to him and 2) leaving the war in protest when he thought it had gone on for too long. He won a Military Cross for bringing in the wounded for 1½ hours under heavy fire. He's also one of the main characters in Pat Barker's The Regeneration Trilogy, in which he struggles with the knowledge that he is safe in England while the foot soldiers are dying in France, and later goes back to protect them.
Lt. Colonel Benjamin O. Davis, Jr. was specifically picked to lead the Tuskegee Airmen because he had survived the Army's segregation better than most anyone and thus could provide both an understanding and leadership to the other Black pilots. Their service record indicates he was most definitely the right choice.
Rowland Hill, a British General who served in the Peninsular War. His nickname "Daddy Hill" just about sums him up. He was reportedly only ever heard to swear on two occasions, and often showed great generosity to both officers and men alike. Not to mention that he was a pretty capable commander.
Ditto other generals in the same theatre, like "Black" Robert Craufurd, commander of the British Light Division (which was one of the best formations in Europe, and the Frenchman Marshal Victor, who was called "le beau soleil" by his adoring troops.
Sir John Moore, who commanded the British Expedition to Spain in 1806. After a combination of Napoleon, poor supplies from home, Spanish incompetence and a brutal winter forced him to retreat, he held his army together through a gruelling retreat, and men still loved him. He died to make sure they could successfully be extracted at La Corunna. There was not time for a proper burial, so:
Marshal Soult considered him such a Worthy Opponent and so respected him that he built a monument to mark his spot.
A rather sinister and almost literal example is Theodor Eicke, known as "Papa" to his men.
Leon Trotsky. When the Russian Civil War broke out, he had the families of some the higher-ranked army members kidnapped and held hostage so they didn't disobey his orders and forced every capable man to combat against the Whites (since the Bolsheviks only controlled the area around Moscow and were forced to fight against over 10 countries). When he was not doing any of these, he would ride on his Cool Train (or, depending on the terrain, his Cool Car) to any part of the front that needed his assistance to hand out cigarettes and chocolates and even appear out of nowhere just to raise the morale of the troops. In his autobiography he speaks fondly of the men he worked with and shows great admiration for who they were.
This could be more or less literal in Highland regiments, some of whom were lead by commanders who were chiefs back home and had many in their regiment who were either blood relations or at least fellow clansmen
The Highlands were an unusual example of this because the organization of their tribal society made a regiment a prearranged package; they just had to gather at their chiefs bidding as they had always done and formal military arrangements were just an add-on. However it was the case in many places that the Colonel would be a local noble who would recruit from his particular district.
Field Marshal Sir Colin Campbell had a very close, almost family like, relationship with his men. This lead to him being able to get them to stand before the Russian cavalry in what became known as The Thin Red Line, two ranks of British soldiers against a massed charge of enemy cavalry. They even began an un-ordered counter charge as the Russians began to rout which he stopped with a cry of "93rd, damn all that eagerness!"
Michiel de Ruyter, a Dutch Admiral who served his country in the 17th century and scored several victories against the English. He was called "Grandfather" by his men.
Grigoriy Potyomkin (yes, that Potyomkin/Potemkin), if the later accounts of those who served under him are any indication. Aside from the usual stuff (and there was a lot of it; he commanded armies in the field, after all), he also used his position and courtly influence to change the Russian uniform; the new uniform was much more comfortable and optimal (arguably the best in Europe at the time) than what was used before and after, and was incredibly popular among the common soldiers in particular.
Napoleon Bonaparte cared a great deal for his men, often working on the front line and living in the same conditions as his men, and going to great lengths to ensure their morale was kept up, as well as frequently praising and rewarding them. The biggest example of this was the aftermath of the Battle of Austerlitz (widely regarded as Napoleon's finest victory), where he gave his men great praise, gave rewards of 2 million gold francs to his officers, 200 francs to each of his soldiers, arranged for large pensions for the widows of his fallen men, and personally adopted the war orphans.
Gaius Julius Caesar. The man would do the grunt work alongside his men at times, the result being absolute loyalty to him.
He is also said to have known the names of most of the men in his army. Considering his soldiers numbered in the tens of thousands that is probably a stretch but he probably knew the names of his centurions and generals.
George Washington was not just America's first president, but also one of her most beloved generals. He would camp with the men and share in their struggles, and would put himself into the thick of fights to keep morale up. He also built up camaraderie with a lot of the younger officers, especially Alexander Hamiltion and Marquis De Lafayette, to where he literally became an adopted father figure to them. By war's end, he would be able to talk his officers out of a planned coup by directly appealing to them with a letter from Congress about their overdue pay: Washington pulled out reading glasses and admitted that in the course of the war he had "gone blind" in service to the country. Manly Tears ensued.
'Uncle Bill' Slim, commander of the 14th or 'forgotten' British army in Burma. When he was defeated orginally in 1941 and had led his men out on one of the longest retreats of all time, they cheered him as they passed.
Hans Langsdorff, the final commander of Graf Spee, sacrificed his honour in the eyes of the German Navy by refusing to take his crippled ship into the waiting guns of the Royal Navy. He chose instead to scuttle her (while giving the old Navy salute instead of the "Heil Hitler" salute) and keep her from the hands of the enemy whilst saving the lives of his 1100 crew. His great 'sin' in the eyes of the establishment was to not go down with his ship, he was in fact prevented from doing so by his own officers. When he got back to shore he ensured his men were safe and looked after and then followed her into history with a shot to his own head. His crew mattered more to him than his life or his honour.
Chester Nimitz, who commanded the US Pacific Fleet for World War II, was frequently described by those who worked with him as remarkably even-tempered. Many people described him as an almost grandfatherly figure, utterly lacking in the ruthlessness that was usually associated with reaching an Admiral's rank; the only burden he would place upon his subordinates was that of his unwavering faith in their abilities. He frequently served as a moderating influence on some of his more acerbic subordinates, and also as shield from the mercurial behavior of his own superior, Ernest King.
Hyman Rickover, father of the Nuclear Navy, was definitely not one of the more personable types - he had no tolerance for stupidity, very high and exacting standards, and wasn't afraid to put a subordinate through ridiculous tests to prove they were capable of serving in "his" submarine fleet. But Rickover never certified a submarine for sea duty without being aboard her during trials, would without hesitation pull a ship from sea duty if he felt there were safety risks, and his meticulous nature was because he didn't want any Navy man serving aboard a submarine that Rickover wouldn't put his son aboard.
Alfred the Great was not just this but practically considered the father of the nation of 'England' having united the various Anglo-Saxon kingdoms under one banner. He was noted for his honour and bravery in battle as well as his keen intellect- well known for being the only English monarch to receive the title 'the Great'.
Sun Tzu recommends this - in moderation. He claims that such connections can improve morale. However, if done in excess, it's a bad thing, considered one of his "Five Dangerous Faults of a General". If the commander sacrifices important advantages for the sake of his troops' comfort, then defeat or prolonged conflict follows. The long-term result would be detrimental to everyone.
Philippe I, Duke of Orléans, was universally admired by his troops for his attention to their needs and his steely bravery on the battlefield. Unfortunately, his brother got jealous and quickly relieved him of command.
Frederick The Great instituted Prussia's first ever social welfare system for soldiers too injured for work, to save them from lives of begging. They loved him for it. At the Battle of Kolin, all it took was for him to ride in front of the flagging 1st Guards and yell "You damned bastards! You want to live forever?" for them to carry the day for him.