Major — happy, bright (W-W-H-W-W-W-H)
Minor — sad, dark (W-H-W-W-H-W-W)
Pentatonic — 5 notes, universal (no wrong notes)
Blues — soulful, adds ♭5 to pentatonic
Chromatic — all 12 semitones

Major — root + 3rd + 5th (happy)
Minor — root + ♭3rd + 5th (sad)
Diminished — root + ♭3rd + ♭5th (tense)
Augmented — root + 3rd + ♯5th (dreamy)
7th — adds 7th interval (jazzy)

W = Whole step (2 semitones)
H = Half step (1 semitone)
3rd = 3 or 4 semitones
5th = 7 semitones (perfect)