Mario is a great game. They have just been targeting younger audiences dumbing mario down. The last good Mario game was galaxy, and before that sunshine, and the N64 had the last continuous series of good mario games (those are always fun, mo matter how old you are.) Mario kart and Party are in the middle. Always good games, but never phenominal.
Mario is an icon of our generation. If you are unable to sit down and find enjoyment at least for a bit out of any of the Mario games, then I don't think you are a true game fan.
You will know Mario until you die. So enjoy him while you last.