Ah, I missed it when they removed those lines form BG2 (For those of you who never played Baldur's Gate, if you clicked on your companion's portrait enough times, you'd eventually get lines like, "Some day Tiax will point and click." and "If a tree falls in the forest... I'll kill the bastard what done it.") I just wish they had more cool ones like that.
As far as fun companions go, 4X is a giant Metal Captain America with all the awesomeness that implies, Gault's introduction is fantastic, and I really enjoy his snarky comments, Blizz is like a little puppy dog who you just can't bare to see upset, and of course your own character has some truely fantastic lines;
The Male Sith Warrior's delivery here is just priceless, and you can tell Vette is barely biting back laughter. And of course the Sith Inquisitor and the SMuggler are just gold in that regard
Yadira Ban: My name is Yadira Ban, and I was sent here to protect the general.
Sith Inquisitor: Really? My first master tried to kill me, too.
[After a rather pathetic assassination attempt and a shield malfunction]
Smuggler: Aww, did the manual have too many big words for you?