Many! But I'll give you my top 7...
7. Streets of Rage 2: Level 1-1 (Go Straight)
6. Mega Man: The Wily Wars - Mega Man 3: Wily Castle Boss Theme
5. Streets of Rage 2: Character Select
4: Columns - Clotho
3. Sonic the Hedgehog 1: Spring Yard Zone
2. Mega Man - The Wily Wars: Mega Man 2 - Wily Stage 1
1. Sonic the Hedgehog 2: Chemical Plant Zone
Can't believe no one mentioned these...