A minor blues scale
The minor blues scale in other keys:

Blues minor scales derive from a pentatonic minor scale, that sometimes also called Rock Scale, blues scales, thought, have one additional note that makes all the difference when they sound, in A minor blues scale it's the D# note.

Blues scales really sound very bluesy, try to improvise playing different variations of notes around the scale, add trills, bends, etc... experiment with phrasing and pausing. It's really easy and fun to play blues solos!