I define epic to be something that is so amazing that it is hard to put into words. Originality and entertainment play a key role in what I call "epic anime".
For me that would be MariMite and Lovely Complex (and KareKano, though I'm not going to talk about it here). MariMite probably doesn't fall in the romcom genre (more towards rom side), but it made me laugh enough.
I liked Lovely Complex, mainly because it didn't make me gag all the time like Ichigo 100% and other titles did (the anime, not the manga; and yes I know the manga is far better). There's still the Coincidental Meeting plot device and a few other devices scattered around, but they're more believable and not so eyeroll-ish. Also, no guy-tripping-and-falling-over-girl plot devices, no non-obligatory pantsu shots, not too much of guy-doing-dumb-stuff, etc.
And for once, the male protagonist is actually kinda cool; aside from his seeming lack of awareness of romantic feelings he's probably one of the few romcom male protagonists I actually liked.
As for MariMite... I usually hate high school anime, but MariMite is so full of poise, grace and style, that it doesn't feel like HS anime at all (also helps that there's little focus on their HS life, more on their personal issues and club activities). Yuri drama = win.
TBH I haven't watched that much romcom yet; putting Itazura No Kiss on the to-watch list though.