I've been playing a lot of heavily distorted metal, and I'd have to say it's giving me a headache. Instead I decided to try to learn the intro solo for one. Does anyone know of any other relatively fun / relaxing clean songs to play?

Agile AL-2000
Vox ad30vt
Orange 20b bass amp
SX SPJ bass
crappy jasmine branded takamine acoustic guitar
maybe try and play some Steve Vai, or go in the more rock n rollish genre.
I started out playing metal, but slowly became more interested in the rock n roll kinda genre, still very technical with sweeps, alternative, tapping and such, but a lot more relaxing, while still being powerful.

For clean relaxing songs, I'd say try Tender Surrender by Steve Vai.
Ibanez s540 with gold Schaller bridge and OMGGOLD hardware

Ibanez RGR320 with Lo-Edge Pro bridge and scalloped fretboard

Lee Jackson XLSC - 500

Roland Microcube

Dunlop Jazz III black
greensleeves or fade to black by metallica (intro solo parts) hmm or nothing else matters by metallica