Dan and Vanessa - Perfect friendship, they're both very considerate
Chuck and Nate - I don't consider it as friendship, they're dull
Blair and Serena - They're frenemies
Jenny and Eric - Not so close friends, too bad there aren't enough scenes of them

I think Dan & Vanessa's friendship is strong too but I know S & B go through a load of crap but they always come out of it best friends and even stronger! =)
Chuck & Nate well are hardly friends anymore are they? Hopefully they can patch things up! =) They were fantastic in season 1! =)
Jenny & Eric - I love their friendship it's cute!

i think jenny and eric r the perfect friends. they hang out a lot i guess. LOLZ

They are the perfect friends, they are always there for each other and never fight.

Definitely!

My favorite friendship is Serena and Blair, but they certainly don't work the best.

serena and blair .. even if they fighting sometimes but they care about each others .. and that is what friendship should be fighting and caring ... Dan and vanessa they same almost perfect and that does't make sense those days !!

I think Jenny and Eric are so cute together they have a good friendship.

I love S and B's friendship but there's definitely some rivalry there. Chuck/Nate for me was kinda ruined after what an absolute douche Nate was being to Chuck all of season 2 basically. Dan and Vanessa... well Vanessa's a part of it so it automically disqualifies it. And I love Jenny and Eric's friendship! It's so sweet.

Come on! Serena and Blair are fighting in like every other episode. Dan and Vanessa are the perfect friendship!

But I dont like it the best. My favourite is Serena and Blair's friendship but it deffo doesnt work best.

Kidding?
Blair and Serena have the shittiest friendship like...ever!

I think that once you overlook the fact that they're two extremely stunning and equally rich girls, lol, they have a kind of friendship that I think is kind of relatable.