I would say Mario 64 hasn't aged very well to today's standards. So in essence... it does suck "now," but back then it was one of the first 3D platformers. Check out other 3D platformers from that year (1996), tell me if they compare to what SM64 achieved, lol.
There was a 3D platformer in 1995 called "Jumper Flash!" for the Playstation. Suffice to say, if you don't know about that, then don't worry, it's one of those old forgotten stinkers that no one paid much attention to. Other 1996 releases that fit the genre are Crash Bandicoot and... (lol) Bubsy 3D. You can't really compare Crash to Mario though since those are two different ways to platform (linear stiff progression vs open miniature sandbox worlds). Those closest is Bubsy 3D but... look, you don't want to play that game, if you want a game that truly sucks, it's that one.
...
Anyways, my little tangent aside...
...I actually, unironically, love Sonic 06 for all the design flaws it spawned. It's one of those "so bad it's good" games, and it's just so immensely fun to play through. Only downside... it eats up a lot of time because you'll spend most of it IN GOD DAMN LOADING SCREENS,
FUCK. If there was any way I could go through the game without dealing with it, the game would actually be one of my favorite (bad but good) games to play through from time to time.
I mean...
You got things like this in the game, and it's just so good.
But as it is...
*sigh*
That title goes to the original Sonic Adventure, goodness what a glitchy mess that game is. The cheesy lines and broken mechanics are just icing on a delicious cake of a shit game.
Iconic and never gets old.