As this topic has been revived, I will state my opinions of the games.
Sonic 1: Colourful and can sometimes be addictive. When I was younger, I used to play this for ages. The gameplay is solid, the music is nice, and the colourful graphics gives you a good retro experience (well for me it did) the only annoying thing is it was a bit short, and Marble Zone's level design was a bit annoying. Sonic is about speed, not platforming to the point where hardly any speed comes into play. Also Scrap Brain Zone act 3 was annoying to complete.
Rating: 7/10
Sonic 2: Not bad, but I've played better. Sonic 2 just tends to be based on speed most of the time, but not to the extent to Sonic Advance 2's it had nice levels, ok music, the gameplay was alright. The things which wern't good was the fact Tails was useless unless you are playing 1P with a friend, or in multiplayer, and the boss fights wern't much of a challenge until Wing Fortress Zone. At least 1/2 of the game wasn't that challenging at all. Although the scenery is nice.
Rating: 7/10
Sonic CD: Amazing, I loved this game when I got it on Sonic Gems Collection, an just couldnn't stop playing it. The music was awesome, the gameplay was nic withthe time travel, and the colourful backgrounds were just classic. It also actually given players different challenges for a change, particularly the instead of hit the boss 8 times till it's scrap heap, as FoxBlitzz saiid, there are different boss challenges that the player has to think of a different trategy to beat them, except the final boss was stupid. Other from that, it was a nice game worth playing.
Rating: 8/10
Sonic 3 & Knuckles: The best classic around, hands down. This game was when Sonic showed his best. The levels were very nice, the colourful backgrounds & graphics were nice, and the gameplay was solid. There's over 20 levels, 3 characters, and 14 emeralds, there is a lot to do in the single player mode. My only dislikes were Super Tails was overpowered, infact I'd say he's a bit more overpowered than Hyper Sonic in some ways even though he was immensely powerful. Also the bosses were a bit of a letdown until the later bosses from Death Egg Act 1 onwards as it goes back to the 8 hit until dead with the exception of Lava Reef's main boss.
Rating: 8.5/10
Sonic 3D Flickies Island: This one was ok, but I didn't enjoy this one in places. The level design was firly cramped in certain parts of the game, bland, and just didn't look like it had life due t it's blandness. The special stages & bosses were also cheap particularly Panic Puppet's boss, and Special stage 6 and last ones. Overall, it was fairly average.
Rating: 6/10
Sonic Spinball: An unique way of playing pinball, the pinball stages were nice, the gimmicks were pretty cool, and it was just another averge fun pinball game with a few different things. Thing that was a bit suckage was Sonic's control in the air, and on the ground as he is slow as a snail. Only his spindash made him fast.
Rating: 6.5/10
Sonic Adventure DX: A very good 3D Sonic game, the gameplay & the graphics were very good. Would be nice if it had more speed though, as it had a bit more platforming in the game. Another annoying thing was the repetitiveness in the charatcer's storie's although certain stories had a purpose to either the characters goal, or a purpose to the game itself.
Rating: 8/10
Sonic Adventure 2 Battle: This one was another good game, the gameplay was fun, the graphics I'd say wern't as good as SADX's but they wern't too bad. Multiplayer was cheap & boring, and the game was a bit repetitive. They need Tails out that mech like in SADX, Eggman would of been awesome out of a mech.
Rating: 7/10
Sonic Advance: Based off the classics, this was actually the most fun. It kind of based off Sonic 2, with the exception of more platforming which made it a bit more fun than S2 itself. Egg rocket was a bit cheap with the death pits, and the annoying level design.
Rating: 8/10
Sonic Advance 2: Oh dear, what's happening here, this game is just an advertisement of Sonic Rush all the way. It badly lacked in platforming, and it was a speed fest. Hot Crater & Egg Utopia are 2 good examples. Also the special stage system was cheap ring collecting wise, and the difficulty in the special stages were ridiculous. Although in some aspects, a few bits of gameplay were ok.
Rating: 4/10
Sonci Advance 3: Not bad, but again, I've played better. Whilst it has Sonic Advance 2's speed, it has Sonic Advance 1's platforming which is not a bad combo. The level designs were actually a decent challenge from Advance 2, and the team feature was nice, although it could be better. Another averge Sonic game.
Rating: 7/10
Sonic Next Gen: This would of been good, but it's the engine is what mostly has screwed this game up completely. The level design was bad, the camera is fail in some parts, partcularly trying to turn around at a certain part of a level, and Silver was stupidly cheap in multiplayer mode. The only 2 good bits were Music & Grahpics. I could go on for ages, but I'll do that another time.
Rating: 4/10
Sonic Unleashed: Actaully pretty good comeback considoring the recent crappy titles. The day time stages were incredibly fun to play in. Also, the graphics were nice, the music wasn't too bad, but the werehog ruined the majority of the game. It should only be daytime stages, and not beat the crap out of weird things, and the game would be perfect. Also, it suffers a bit of Sonic Rush with the speed boosts. The power should ton down just a small bit. The 2D to 3D & back was a very nice feature however.
Rating: 7/10
Sonic Chronicles: Not bad for a first Sonic RPG, the battles were neat, the story was actually pretty decent for a change, and the the character talking in the speech bubbles were nice, because it felt like I can direct the whole scene here, and find different reactions with different characters, some stupid, and some quite humerous. The only drawbacks were the sound was very high, it killed my ears, and the music was horrible except diamond dust remix. If the sequel does go ahead, they better have better music next time round.
Rating: 7.5/10
More to come