Im one of those guys who likes to stay ripped all year round. Genetics plays a big part as i have very high metabilosm and i had great abs since i was a kid.
I never diet and basically try to eat as much as possible. I ski 2 times a week during winter which does wonders for the abs and keeps me lean even tough im bulking like a madman. Any cardio training will do the trick tough.
During the summer season i eat less and run more.