I would think they would want their girlfriends to treat them with respect but can sometimes joke around with them, who can have a serious conversation but can make them smile anytime and anywhere, who isn't clingy, desperate or overly-obsessed but shows she cares for him a lot and shows how much he means to her, who talks to him and tells him everything but doesn't get into details or make it all about her.. A guy needs a girlfriend, a bestfriend and a bud- try to be the first too and leave the other one for his guyfriends :)
I know you wanted a guys opinion, but I thought I might try and see if guys agree or not, so I hope this helps you answer your question, but guys leave a comment or rate :)
Again, Hope this helps! :)
Just remember, not all guys are the same, and they could agree with all, some or none of the things I just said :)
For me it would just be to not take anything I say too seriously, I like having light-hearted banter and making jokes (even if they're rude/offensive).
Also, just respect the way a man's mind works in regards to emotions. We won't feel as strongly about some things in a relationship as girls do, and most girl mistake this for them not being interested in them, or 'not caring'. This doesn't mean don't show love and affection to him and expect the same back, just be aware that guys are generally bad at communicating their feelings, and it doesn't come as naturally as it does for girls.
respect and consideration..
also little things count a lot, like eg you go to the cinema, he buys the drinks etc, you get the straws, then don't just give him, but open it and put it in the drink for him...or stocking a drink he likes in your fridge, etc... I don't know, but those little things are what made me fall in love with my gf...lol