I got the over under type because I figured its easier to access the coin bank, and although I'm going to have it wired to require coins for credits, it's purely authenticity and nooone will have to actually pay, I plan to have a dedicated pile of coins recycling. I don't think I have willpower to save money by keeping it inside there either.
Of all the games I would have nostalgia for dropping in a coin, the biggest would have to be arkanoid. Whenever I'd play that I'd anticipate the bassy coin insert, and if I put more than one credit in, I'd do it slowly to get the full audio as many times as coins put in. The day I had this ability in Mame was a good day. I think I'll go press 5 a few times now...