Since when was Shadow Hog a mod? Good for you, man. You people should really start announcing these sorts of things.
But I digress. This is a topic that's been nagging at me for the longest time, so I'm just going to take the best games I can think of off the top of my head and try to sort them out. It's hard for me to play favorites with any of them, and my preferences fluctate depending on how recently I've played a game, and how much I've played it (S3&K would be pretty high up on this list if it weren't so stale for me now), so yeah, my opinion isn't really final.
1. Silhouette Mirage
2. Metal Slug 3
3. Alien Soldier
4. Twinkle Star Sprites
5. Radiant Silvergun
6. Dynamite Headdy
7. Panorama Cotton
8. Sonic 3 & Knuckles
9. Croc: Legend of the Gobbos (Sentimental reasons, mostly)
10. Clockwork Knight (2, namely, but they're both practically the same game)
I am a man of fine taste. On a side note, Mystic, Twinkle Star Sprites is right up your alley, you should totally get into it. All of you should. It's loli galore, and I really need someone worthwhile to play with.