I'm with you on most of this (expect Big the Cat, i genuinely dislike his levels) I [layed Unleased on Wii and honestly enjoyed the werehog levels. Seriously, the only thing I dislike about it is why the hell the choose to make him a werewolf (it just doesn't make sense). And I recently got Sonic Lost World and if the controls were a little more like the 3ds, i reckon it would be one of my favourite Sonic games. The level design is just really cool and it looks so pretty too! Plus it's 60fps (I believe)If you haven't played anything after the game gear/genesis stuf for more than a few hours, then you have a lot to catch up on from more than the past five years..
Sonic Adventure is in my opinion one of the best Sonic games ever. Sonic Adventure 2 is great. Sonic Heroes is good. Sonic Unleashed is also one of the best Sonic games in my opinion (make sure to get it for ps3/xbox 360 as opposed to wii/ps2). Sonic Colors is good. Sonic Generations is great. Sonic Lost World is good.
I've honestly enjoyed the 3d Sonic games and found often complained about traits (Werehog stages, Big the cat, Heroes teamwork, etc.) are either overhated or actually fun. I'm not guaranteeing you'll enjoy the games since everyone's mileage varies, but you should try playing through each of them and develop your own opinions.
Honest, my least favourite Sonic game is Colours for Wii and it's barely bad. The only complaint I really have for it is that you get very little in the way of Boost energy ( I always seem to run out)