Hmm... i wouldnt say every 3 months, i dont think there is any. But, i do tend to give Sonic 3 & Knuckles a go every year. Nights aswell on christmas time, though i didnt last year.
Sonic 3 & Knuckles is the game i replayed the most during my life. I confess i'm a bit tired of it now. Not the gameplay, but the same levels. I want new levels. ^^