Kirby simply because it is a series that always makes me smile. Even the bad ones in the series do that. Ratched and Clank be a next one in that it is fun simply in there design they make the same game like Mario every so often and is fun. I know different story line and different stuff put in, but it keeps to the same formula. It's a f**king good formula, but it is the same formula. It is how I understand how Madden fans buy the same game every year.
To those that say Half-life you have my personal f**k yous. This is because a good chunk of what I hate in gaming in general is because or related to Half-life, and is made popular because of Half-life. The people that love this make it reasonable to make more of that kind of crap just like the s**t head youths that justify raping Sonic, and hate you for that.