Along metal lines, I really like this one:

A5----F5----G5----Emaj(first inversion on the 4th fret).

It uses both regular and harmonic minor, giving a melodic metal sound. Royal Hunt uses it a lot

One I came up with is this:

E----B----F#--------Gm-A----E----Bsus2----F#

Each chord is played one measure long except the first F# which is almost 2 measures with the Gm rounding it out leading into the A chord. What's nice is you start in E major, but end up in F# major. It's not completely diatonic.