Good but a Bit Long
I watched this movie thinking it was like Superbad (2007) - it stars Jonah Hill, after all - but found it a little disappointing. It starts off quite well with this guy, Ben Stone, a Canadian, living with his 4 pot-smoking buddies. Ben gets lucky one night with Alison, a "Norse goddess", over too much alcohol. Alison then finds out she's pregnant and Ben, naturally, tries to do the right thing. There's some pretty good (but perhaps a little vulgar) humor which makes it worth watching.
Even so, at over 2 hours, it slowly morphs into a kind of drama about the virtues of marriage and kids. A sort of growing-up experience for a man-child. There isn't much character development as far as Ben's buddies go, though. It's essentially about him and Alison, and her sister Debbie and her husband, Pete (a good performance by Paul Rudd). Personally, if you're looking for humor, I'd recommend you go with Superbad, but take this one as a reasonably-close second. You won't remember Knocked Up for long, though. There's nothing that really stands out. Kind of like what Ben remembers of his night with Alison.