I've always enjoyed adventure birthday stuff. I like doing stuff that I've always been a little scared to do... keeps me young That could be another option, if there is something you've always wanted to do but were a little afraid of.
I know someone who's having a hot air balloon ride for her birthday- always wanted to, never did it, so she figures she'd better.
If wisdom’s ways you wisely seek,
Five things observe with care,
To whom you speak,
Of whom you speak,
And how, and when, and where.
Caroline Lake Ingalls