While there isn't any romance this time around, pursuing friendship with your new companions also sets up some good moments. Nathaniel showing genuine gratitude for being given the chance to redeem his family; Sigrun finding closure with her past sins; Velanna overcoming her Fantastic Racism and deciding to create new stories for the Dalish rather than obsess over lost history; Anders playing with a kitten and (possibly) finding a new home with the Wardens; the Spirit of Justice marveling at the inherent beauty of the physical world and of friendship... they aren't quite as well developed as the Origins companions, but still.
The Kal'Hirol questline has one. The spectres of Kal'Hirol's inhabitants and their darkspawn attackers can still be seen while you wander its halls. At one point you witness a warrior addressing a crowd of casteless dwarves asking them to take up arms in defense of their home to prove to everyone that they aren't "dust". You later see that same warrior's last act before being mauled by an Ogre: recording the names of every casteless dwarf that died defending Kal'Hirol — he wanted them to be remembered as warriors, not forgotten like every other casteless. It's a welcome change from seeing most dwarves in Orzammar treating the casteless like crap.
It's taken up a notch when you can then take that tablet to one of the dwarves in your Keep, and have them forward it along to the Shaperate - allowing the names of those casteless to be entered into the records of Orzammar officially as defenders of Kal'Hirol.
Sigrun's eternal thankfulness for the simple pleasure of being allowed to use the castle library. Since she was born casteless, she had been illiterate for most of her life; but after joining the Legion of the Dead, a fellow Legionnaire taught her how to read, and she learned to love it... but they only had one book. This is the first time she's allowed to enjoy a simple hobby that most would take for granted.
A possible epilogue for Sigrun:
"Although Sigrun seemed intent on leaving for her Calling, departing for the Deep Roads to finish what she started in Kal'Hirol, the Warden-Commander had a knack for finding important and absolutely urgent things to occupy the dwarf."
Anders' epilogue, if he survives the storyline and you've completed his personal side-quest: He stays at the Vigil's Keep for a long, long time and when he finally decides it's time to leave, he comes right back not two months later because the Wardens have become more than just a job for him; they are now his home and family.
Nathaniel's epilogue says that he spends his days helping people, righting wrongs and generally being a good guy. But the best part? During his travels he saves Fergus Cousland from a bandit attack and Fergus officially forgives Nathaniel and the Howe family for what Arl Howe did to the Couslands, restoring their good name. It's a truly Heartwarming Moment for both characters, doubly so if the Warden is a Human Noble.
Just befriending Nathaniel as a Human Noble is itself a CMOH. Both characters have good reason to hate each other and seem to be on the verge of starting a vicious Cycle of Revenge. But the two are able to set aside their differences and team up for a greater cause in defeating the darkspawn, giving Nathaniel a new purpose in life. The two get to know each other, and, once Nathaniel has come to terms with how horrific his father really was, eventually form a friendship based on mutual respect and trust. Rather than seeking revenge, the children of both families are able to put aside the hatred sparked by one man and find a peaceful resolution with each other. If that's not heartwarming, I don't know what is.
Particularly since the backstory revealed that Arl Howe's actions were merely the latest in a long history of clashes and feuding between the Howes and the Couslands, which has stretched back centuries. The Howes were effectively vassals of the Couslands, but it was a long-standing belief in the Howe clan that it should have been the other way around, and this was reflected many times in the families' relationships. The Human Noble's father, Bryce Cousland, thought he had managed to reconcile the two families, but let his wartime friendship with Rendon Howe blind himself to what type of person he really was. What a better tribute to his memory than both the Human Noble and Fergus refusing to seek revenge and instead finally burying the hatchet with Nathaniel, ending the bad blood between the two families, once and for all.
And there's another option for recruiting him besides conscription. When deciding Nathaniel's fate, you can just let him leave with what he came for. When the seneschal objects, you can point out that they are his family's possessions, and the worst he's guilty of is trespassing. Nathaniel is so grateful that he comes back and volunteers to go through the joining.
Completing the "Maferath's Monuments" quest in the Wending Wood, and reading the finished Canticle of Maferath. While it's not surprising that the setting's resident Crystal Dragon Jesus would forgive her husband for his betrayal (especially since it was the Maker's plan), it is uplifting to see Maferath go from a remorseful wreck into a man striving to redeem himself, at peace with his past actions.
Bumping into Wynne again in Amarathine, particularly if she was befriended during Origins. Furthermore, it proves she was wrong in her last conversation post-coronation, because they did see each other again.
Depending on your choices at the end of Origins, the epilogue of Awakening can say that the Warden stayed around long enough to see the darkspawn threat ended and the people saved, only to once again leave, chasing after a certain "dark haired sorceress". The Warden, giving up on Morrigan? He'd die first.
If a male Human Noble Warden married Anora in Origins, then at the end of Awakening one of the epilogue slides will state that when the Warden finally returns to her side, she's glad to see him. Considering her usually stuffy nature, it's a rather nice Aww, Look! They Really Do Love Each Other moment.
Conversely, if a female Human Noble Warden married Alistair, he has a fun cameo at the end of the DLC's prologue which clearly demonstrates how strong and affectionate their bond continues to be. The epilogue slide says that when she returns to court, her husband is beside himself with joy to have her back.
Wardens who romanced Zevran or Leliana are treated to letters from their beloved.