1.Tool. Tool. Tool. Tool. Tool. Tool.
Actually, Maynard in general. APC and Puscifer, too. But especially Tool, and especially if you know and appreciate the lyrics.
2. Pink Floyd.
3. Crosby, Stills, Nash, and Young
4. Classical music
Honestly, in my experience, if it makes me feel good at baseline, it makes me feel amazing on drugs.