I wholeheartedly recommend this game as a great way to relax after a long day of work/school.
For the most part, the characters around the table are fun and have lots of personality. If you know their history, its nice to see these licensed characters play poker the way one might imagine. But even if you've never heard of most of them, you'll come to know them - and their interesting quirks - in short order.
Sam is conservative with his betting, almost achingly so. Ash is just as keen on bluffing as he is on raising the stakes - he *wants* the player to squirm. Brock comes across as more studious with his bets, but won't hesitate to bet big when he feels he has the advantage; it is fun to just *watch* Brock think. Claptrap is a wild card, and he knows it; he is fairly easy to intimidate and he seems eager to win the approval of his competitors. His failures - and constant excuses - will make anyone familar with Borderlands want to hug him....and then hit him in the face.
What makes the game particularly fun is that the characters seem to actually enjoy each other's company. The lines are well read and the timing of their usage accurately reflects the events of the match. GLaDOS is a perfect addition as supervisor for the evening's events - just as much as the other characters seem to like hanging out together, GLaDOS seems just as eager to be rid of them. The dynamic works extremely well in keeping the match engaging.
As for the poker itself, its pretty conventional stuff; no doubt you've played similar games with similar mechanics before. But the matches move right along at a good pace, and the "Showdowns" are enjoyably tense. These moments also have the funniest lines, in my opinion. (...Brock...poor Brock...)
In sum, Poker Night 2 is a presentation 'tour de force' with very competent game mechanics. If you like card games, its not one to be missed. Oh, and the price is great, too!