Xbox 360. It has some memorable exclusives plus a huge amount of games, the first iteration of achievements (also the best), an awesome interface (until MS ruined it at the very end, but at least vanilla and v.2 were damn great) and brought a comfortable controller (shame about using batteries, but you could always buy one of those wired ones). It also had some smooth online interactions and allowed for a good experience overall.
It had its flaws, RROD and certain other issues, but I personally love it. It was my favourite seventh gen console and one of the best consolles overall imo. It also had some unique charm, can't really describe it. Something the Xbox One is lacking, and I'm not sure MS would be able to recapture it ever again. It was also a different era back then, but still...
