Any really good Sidescrolling Shooters out there?

[Skulkraken]

You should play Iji.



http://www.remar.se/daniel/iji.php

[MANDRAG GANON]

Umihara Kawase (snes) is fantastic, the physics are lovely.
Any of the Haggleman games from Retro Game Challenge (DS) are pretty good, Haggleman 3 you might be particularly interested in.
Exile (C64) You Might enjoy if you liked Jetpack.
Blaster Master (NES) is similar to metroid gameplay.
Jill of the Jungle (DOS) I always loved as well as alot of the games Franpa said
Commander Keen (DOS) is just amazing.
Legend of Kage 2 (DS) was great, it can be fairly linear at times but it was enjoyable.
Layla (NES) Something i've been playing lately that's alright
Clash at Demonhead (NES) Weird but fun
Kabuki Quantum Fighter (NES) This game doesnt have shooting really but you headbang people to death.
Little Samson (NES) Similar to megaman, you can choose from 4 characters..
Saiyuki World 2 (NES) This reminds me of Dragon ball kind of. You beat people with a staff.
If you like Flashback maybe try Another World
You clearly enjoyed the Zelda Game Konjak made so you'd probably Enjoy Noitu Love 1 or 2
Rocket Knight Adventures (Genesis)
Sky Blazer (SNES)

I could go on forever. These are fairly obscure as I'm assuming you've played most of the well known games.

[ShadowTiger]

Wow, thank you (all) so much. :) I think I'm good for about a month with these, lol! ^^, I'll definitely be giving Kage 2 a try; I do need something to do on the DS, and my R4 is rarely used to capacity.

[Beldaran]

You should play the Commander Keen games.

[CaRmAgE]

I agree with a lot of these choices, although I'm surprised Bio Menace (DOS) hasn't been mentioned yet. It's a good game to try in case you want the extra challenge.

[ShadowTiger]

Both were definitely very good. :) Played 'em when I was like, four.

[Gleeok]

When I read Side-Scrolling Shooter I for some reason read it as 'Horizontal Shooter' and immidiately thought of Gradius V, which is so good that it cannot really be compared to others like it, that wouldn't be fair, It's more like a God to them.

For side-scrollers I can only think of the usual suspects: Blaster Master, Mario, Contra, Cave Story, Megaman, etc.. all which have been mentioned.

There were some great Neo-Geo games and tons of other arcade hits that probably never made it to a console in America. I do suggest you re-calibrate your M.A.M.E.-o-Meter! It may be due for a tune up.

[Nicholas Steel]

Debris32 by MVP Software is a fantastic comet busters clone, it is a bit hard to come by the game these day though because it infringed on copyright and the company was closed after it was sued. It still is the best Comet Busters clone to this day

[Vagla]

For the NES, try out Ufouria and Gimmick!. Both are fantastic and worth your time, and are relatively unknown because they didn't come out in the US. Neither involve shooting, but Ufouria is very Metroid-like (a massive world to explore, nonlinearity, tons of secrets) and Gimmick! is super polished and a lot of fun. The music for both is really good, too (particularly Gimmick!).

[Beldaran]

Metal Slug is fun.