Looking for a good side scroller beatemup

Hey,  
 
I've been playing streets of rage 3 and that fan remake (am i allowed to say that? i dunno.. ) and i have been searchig for something similar to that but i find most of the good beatem up games are single player, or some type of online battle mode. which really doesn't appeal to me, is there anything i can play with a friend.  
 
By the way bare knuckle/streets of rage, still one of the best games. 

arent 90% of side scrollers beat em up games ?   you scroll sideways and.. beat motherfuckers up 
 
anyway, Shadow Complex? Rocket Knight? Iunno...

Golden Axe is a pretty fun one on XBLA

First thing that came to mind was Castle Crashers, as mentioned above. Just download some trials and see for yourself.

Soon enough you can play Shank.
 
Although I doubt thats co-op......