We've all seen guitars with 19, 20, 22, and 24 frets.
Some guitars have 27:
That's pretty cool.
Some have 30:
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This one has 32 and a sweet dragon body. The last 3 frets are spaced as whole tones (probably because if they were half steps it would be hard to hit the right fret). Bonus coolness, the 7th string is fretless.
This one has 36. On the closeup, look at how small those frets are. That's awesome but I bet it's hard to play.
I had a 29-fret Collen archtop for a while. If you tune it to B, you have the range of a 24-fret 7-string.