Of all the friends from Friends I'd want to hang out with Ross the least, because his anal retentive nature and sniveling would make me want to mash him. Plus I'd probably want to hang out with Phoebe the most and they're practically polar opposites.
Thankfully the Friends are fictional so we don't really have to worry about which one we'd hang out with, but according to 22 Words I was right about Ross being the worst of Friends.
Added to my list of reasons- because he lords his intelligence over everyone, overthinks everything and is prone to emotional outbursts that make everyone, including his own sister, want to slap him.
And finish it off with that whole "will they, won't they, why did he cheat on her?" thing he had going on with Rachel, that really rubbed me the wrong way, Ross! You deserve to be alone with your dusty old bones!
Why do you hate Ross Geller? Yeah, me too. *hugs*