Nice to see someone else remembered the TI 99/4A's voice module. When my brother and I were kids, our babysitter had one at his house and we'd use to play Parsec all the time with that. It was pretty cool. The Intellivoice is still pretty impressive considering the technology at the time, as someone already mentioned with Bomb Squad.
Probably the one that REALLY caught my attention was when I first played Jinks on the 7800 and heard the "YOW" and the other sample from Gauntlet. Oh, if they only released that game for the 7800 back then with those sounds, but no luck.