I 
really like 
these  low-profile black-rimmed buttons (Rick is the only vendor I've found that stocks these  

) with inkjet printed inserts on Avery 18665 or 8665 labels.
The ring between the nut and bezel is removable.

There are many vendors that carry translucent-rimmed or "sawed-off volcano" LED buttons.

I usualy get 12v LEDs and power them with 5v -- not as bright and much longer lasting.  

PROTIP: Get white LEDs for yellow buttons -- yellow LED + yellow diffuser = muddy orange. 

If you're looking for a smaller diameter non-LED button, there are some options but these won't mount without routing a pocket on the back of a 3/4" panel.  IIRC Paradise Arcade Shop and/or Focus Attack carry these.
Seimitsu PS-14-GN-C -- 24mm convex, threaded, clear cover
Sanwa OBSN-24 -- 24mm convex, threaded
Seimitsu PS-14-DN -- 20mm convex, threaded
Sanwa SDM-20 -- 20mm concave, locking tabs
Sanwa SDM-18 -- 18mm concave, locking tabs 
Divemaster has 
these but they're intended for a service panel mounted behind your coin door.

Scott