I support Sunshine Angel! Pretty much what you are looking for :) It fits almost perfectly into ur criteria (and i don't say perfectly loosely)
Also, u may want to consider Fugitive:Plan B - it's a lot of action, A WHOLE LOT of revenge (it's pratically the whole story), considerable amount of romance, and considerable amount of the heroine's time in jail (he got thrown in several times and got out too) Starring Rain(Jung Ji Hoon)! Hehe....it's basically the guy, who is a detective, working for the girl to find out the truth behind her family's murder. They got into trouble quite alot of times, and there was a time (or quite a few times I would say) when either the guy, the girl, or both of them were beaten down badly by the bad guys. But they rose up and defeated them together...the relationship between the guy and the cops got pretty interesting as well. The cops were chasing the lead guy and girl because they kept breaking the law, but they broke the law because they were catching bad guys...and soon the cops teamed up with the leads (though somewhat still wanting to arrest them). Really funny at some parts! Action-packed, too...give it a shot! Pretty hooking!