You are missing out.
Try Unleashed, Colors, an maybe Heroes. Shadow was an odd game, but it's definitely worth trying too. Especially if you played SA2. (its more or less a sequel to SA2's story, or at least tries to be)
Heroes is the 2nd best of the Bad 3d Sonic era, the only issue that makes the game unplayable at times is falling through the stages, its probably just me, but I fell through the ground so many times I was in a pure rage state at times, besides that, the game is Great!, the multiple characters have variation and the story has metal sonic... sorta...
Great game, but this was one that you wish Patching existed back then.
Shadow the Hedgehog, Fucking stupid, this is 5 steps away from the 2006 Sonic game.
Starring a Brooding Shadow, who Broods about not remembering a Past worth Brooding over. Kill me please...
The Camera cannot Keep up with you, and mind you this game was in PS2 era, and it was a NES era problem.
I can get Shadow with guns, but Vehicles Make no sense when you can OUTRUN THEM.
the multiple endings and story variations were a very good idea, too bad they put it in a shitty game.
Unleashed wasn't too bad, The Controls are very off for a sonic game but the Running Stages are really awesome.... until...
You Transform into the werehog, first impression is "Fucking Sweet, I'm gonna do some collateral damage!", NOPE!
Aside from your Rubber Limbs, Were-Sonic gets De-buffed very Dramatically, the enemies you breeze with like a Jump now requires 20 hits.
that's the only problem, aside from that its a pretty good beat em up, but it would have made more sense to make a new Character for those parts.
Sonic 2006, an abomination starring Goku, Vegeta, and Trunks. oh yeah, BEASTIALITY! not only was this game Terrible, but it was also gross.
Sonic's Story book games (7 rings, Black knight), I heard they were okay, but I also heard they suck, didn't bother since I gave up on Sonic all together after 2006.
I recommend Unleashed and Heroes, but for the love of god do NOT play shadow, its the Highlander 2 of shadow's mythos