I use walnut for all of my axles.
You should probably base your wood choice on the weight you like and/or aesthetics ( my favorite is walnut-beautiful; love the smell too :D)
Cherry,walnut= light
Oak, maple= medium
Purpleheart, bloodwood= heavy
I personally like lighter weight wood for stalls and kickflips; heavier wood is good for more adventurous tricks that require a little extra spin time- but are not forgiving on the knuckles if you make a bad catch 