I spend most of my days playing countless Versus matches on Advance Wars, which not many were into. My most fond memories of games are the old GBA ones and such, and so I still play them to no end!
I dunno, there's lots of series that don't get enough recognition. Some off the top of my head:
S.T.A.L.K.E.R is my favorite FPS series, Metroid is my favorite Nintendo series and it doesn't get as much attention as it should IMO, Total Annihilation is an amazing old RTS that I still play at least once a day, same with Dark Colony. (Another old RTS that I found amazing, but never went anywhere. Plus it's getting harder and harder to play comfortably on my computer considering it hasn't aged well from a technical standpoint. ) I could go on and on about great, obscure games that I've had the privilege of playing!