I was a huge Sonic kid, only had a ps2 during 6th gen so my introduction was Sonic Heroes. When I got a Wii I went back and played the Adventure games. I have mixed feelings on them as an adult, I like pretty much every entry during 6th & 7th gen besides Shadow & 06 since I adored them so much as a kid but I can very easily see the cracks in them now and honestly I don't think I would care for any of them besides Colors & Generations if I didn't grow up with them.
Some games I loved as a kid that 100% hold up as an adult for me however would be Ape Escape 2 & 3, Mario Galaxy 1 & 2, Super Monkey Ball DX, Aqua Aqua, Klonoa 2 & Wii remake, Pac-Man World 2, ExciteBots Trick Racing, and my favorite game of all time which got me into JRPGs Xenoblade 1.