These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
See The Ultimate Showdown of Ultimate Destiny. That is the only mode anybody will ever want to play online in the second game. Taken further in the Xbox version, which had Downloadable Content mostly remembered for porting the mode to more maps and spreading the mode's influence, despite the content including other two new heroes to play as and some maps ported from the first game.
When people do play other modes like Conquest and CTF, expect both teams to be made up almost entirely of heavies and engineers.
Demonic Spiders: Gamorrean Guards are this in Jabba's Palace, as they take an absurd amount of punishment, have a habit of spawning in the middle of already heavy combat zones, and can kill most non-hero units in a single hit. Even hero units have to beware, as they are prone to being knocked over with one hit before being killed by the second.
The Wookiees in II. They have above average health, access to drones, and a grenade launcher. The Wookiee crossbow is a combination of a sniper rifle and a shotgun! Using various levels of charge on the gun can enable it to either spread out and hit more targets, of fire a single, concentrated shot. Add the scope for the sniper rifle part. Access to grenade launcher allows a Wookiee to go against vehicles, adding to the insane versatility of the berserker. The only class barring hero that counters a Wookiee is the Dark Trooper whose ARC Caster can do more damage but lower health, reload and charge times means you have to have a really good escape.
Heroes as well, particularly the Force Push ability. Ordinary characters cannot block Force powers, even with another hero blocking. In the first game, if you didn't get a vehicle to run them over with, you would almost certainly end up dead in seconds, then start raging nonstop as it happens over and over again. Oh, and you couldn't play as them. The sequel, on the other hand...
Engineers, especially in the second game. They all have shotguns (which aren't the standard Short Range Shotgun), the ability to slice the drivers out of vehicles, and the ability to heal and restock their own ammo. There are a common choice for going One-Man Army on the enemy team. Also, fighting while being mostly underwater makes it very difficult for AI enemies to hit you.
Turning friendly fire off could do this, especially with the Heavy Ordinance classes. As turning off damage to teammates also turned off damage to yourself. Let's go over a short list of what you can do with friendly fire off. You can spam grenades and/or machine gun fire down a tight hallway without any regard for your allies, fire Rockets at enemies at point-blank range, pie people in the face with tripmines, pie tanks in the face with tripmines, render enemy command vehicles entirely useless by running underneath them and pieing them with mines. And, my personal favorite, stick mines on to a speeder bike and drive directly into enemy tanks.
The award weapons in II are this trope in spades, most notably the award rifle, shotgun and pistol. The award rifle turns enemy soldiers into hamburger meat faster than you can say "I am your father", the award shotgun one hit kills even the toughest enemy soldiers, and the award pistol is a mini Sniper Rifle that fires as fast as the original pistol.
Harsher in Hindsight: At the end of the second game's Felucia mission, the narrator says that he hopes that when Aayla died in Order 66, it was quick, painless death, saying that she deserved that much for saving the Unit's lives on the mission. Yeah,about that...
Hell Is That Noise / Nightmare Fuel: Airless/underwater/toxic environments. Especially after hearing the horrible choking noise your character makes when they go into them.
That choking sound is made worse with Force Choke. Not only does the sound play when on the receiving end of Force Choke, but the screen turns red when your character is almost out of health. Talk about a near death experience...
Darth Maul appeared as a Hero for the Seperatists despite dying in the Phantom Menace. However, he survived in "The Clone Wars".
Most Annoying Sound: Officers call out whenever there is a change in control point status, near the end of most matches expect to hear a lot of "A command post is no longer under empire control. We've captured a command post. A command post has fallen to our enemies. We've captured a command post. We've lost a command post, take it back!".
Of course, they have such awful range and such low health that you can hand them their asses if you ever get in a fight where you can actually see one of them.
A glitch in the Tantive IV in the second game allows the player to leave the map and walk around it from the outside. If you're fighting another player and both of you know the glitch, this can get really paranoia inducing as they can literally come from anywhere.
Win The Crowd: The internet let out a collective Big "NO!" when it was announced that Electronic Arts had obtained the license to publish Star Wars games... Until the Battlefront reboot was announced, turning the reaction into a Big "YES!" (though some are still worried about EA's financial decisions affecting the game).