JMich: I still think of UAC as the beeper of the seatbelt. You know why it's there, you know that you do want to change things, but it's best to remind you for the 1 time that you didn't want to mess with it.
As for the old games, either do not install in program files, but to a dedicated games folder (C:\Games), or simply give the game's folder in program files full control for your user. For the gog games, I've just given me full control in the "C:\Program Files (x86)\Gog.com" folder, and no more UAC problems. I'd still go through all the UAC hassle though than having to clean my computer from any crap that may slip through, since a format is something that I can't afford (not moneywise, but timewise).
Bah, i'd rather use a GOOD "real" AV program to silently block unwanted intrusions and file alterations/downloads in the background like a smart user and not have some crap M$ kiddy-safe app. running all the time asking me crap like: Asking every time I change shortcut details, when I want to rename some files(non-system ones), asking me for the hundreth time if I really want to run that MalwareBytes or other AV application, asking me all the time for some apps with UAC verify built into their shortcuts like Fraps/etc, moving files between drives, etc.