I want a sandbox Knuckles game. I love Sonic games and don't cry about every aspect of it like most people, but I'm tired of playing as Sonic. I want to play as someone else. And Knuckles gets NO attention anymore. He deserves a huge open exploration game to himself.
I just feel like Sonic never needed to move into 3D, and it really, really, really never needed much characterization or story. I enjoy the gameplay of some of the later Sonic games but I liked it better when it was a "shut up and go really fast!" series and what passed for "cutscenes" was a 20-second pause in gameplay where Robotnik (or Knuckles) showed up, ruined your day and left. These were flat characters and trying to tell more complex stories with them... didn't work for me. Especially when they tried to get serious. Sonic 2006 was an unforgivable disaster of storytelling.
Sonic is one of those series that I think should just stick to formula, because the formula was good.
I still love playing Sonic 2, Sonic 3 & Knuckles, and Sonic 1 (in that order) from Sonic Jam. Of the handhelds, I love Sonic Rush Adventure and I thought Sonic Advance 2 is nice. Of the moderns, I love Sonic Generations (PS3) and actually liked Shadow the Hedgehog game (don't hurt me).
Despite that, I lost interest around the first Sonic Adventure. I normally didn't care for 3D platformers and Sonic Adventure didn't change my mind. In fact, I couldn't stand the Sonic Adventure series anymore mostly because I felt those games are the reasons for the alternate gameplay styles and the trying-to-be-epic storylines. Plus it doesn't help to constantly hear from the fanbase "Make Sonic Adventure 3! That'll save the series!" Give me a break. I know I'm being hypocritical because I like the Shadow the Hedgehog game, but even then, I didn't think that game is appropriate for Sonic. Sonic is getting better but as much as I love Sonic Generations, it's not really great because it was unique in its own right. If Sonic is to be truly great like his classics, Sonic Team is going to have to take it up a notch. As far as storyline is concerned, I didn't think Sonic games had any good writing to begin with. I didn't mind Sonic Generations' because for once, it was a fun main Sonic game through and through.
Can't believe I'm saying this, but I have to agree with ~hoggys2much, maybe with just a little less...murderous rage Sonic before 2006 was gold. Of course you will always have "purists" who will claim that Sonic died the moment he made the transition to 3D. But if that's so I wouldn't blame the medium (after all, Mario transitioned to 3D very successfully) I would blame changes in the games style, atmosphere, story etc - which would have occurred in any dimensions eventually. I say blame them trying to force down a story into it while the competitor - Mario, decided to play it safe and just keep it to little more than "Bowser kidnapped Peach, off to save her ass again!" I believe a lot of early Sonic's charm came from the simplicity of the games - like any decent, entertaining platformer all you had to do was run from left to run and beat a few cute-looking enemies and some kickass bosses and little much else than that
Also the level designs too. If there's one thing that I feel is missing from newer Sonic games - its the presence of inspiring natural worlds. They seem to go more "urban" these days and they saturate them with too many city/factory type levels and neglect places like snow mountains, beaches, caves, volcanoes, forests etc. While older games had those too, but only about 2-3 in an island landscape otherwise filled with colourful, natural wonderlands. My only gripe with Sonic Adventure 2 would be just that - more than half the game was in either the city or space colony. A few more nature levels would have been appreciated. But still - fun game, with heaps of content to work on for the perfectionist Sonic Heroes was the last Sonic game released that I still think is worth bringing out for the occasional "nostalgia-play" today. And the level designs, colours and mood of that game was very true to what originally made Sonic games so inviting and fun. They outta do more games like Heroes if they want a good 3D reputation (of course, don't rehash the team thing, imagine a game like Heroes again just with Sonic as the playable character) - I'd buy it
The Sonic franchise and some of it's more rabid fanbase can be summed up in one image: Actually I quite like some of it. Sonic 2 is my fave of the classic games. I'm one of the rare individuals who considers it better than Sonic 3. Sonic Generation's gameplay is near perfect except for the fact it still really wasn't designed around momentum properly. It tries but kind of falls short of nailing it like the genesis games did.