not a dumb question at all
otherwise it wouldn't be brought up all the time.
All types have advantages/disadvantages...
MDF - Heavy, Lots of sawdust, Smooth without TONS of sanding, Easy to work with
Plywood - Lighter, Stronger, Harder to work with, expent to sand a TON before painting
There are some others out there... but these seem to be the favorites.
going with 3/4" is good because you can use standard T-molding (good thing... 1/2 - 1/4 the price I believe).. And for cocktail tables you can use standard glass clips.
3/4 plywood is overkill on strength... But that isn't a bad thing..
Am I forgetting anything?
I go with MDF for control panels myself.