I played Roller Coaster Tycoon from 1999 recently. That was the exact opposite, and so refreshing. Its an efficient game, which I think it had to be to run well back then with the simulation of 1000 individual guests and the whole park on a Pentium 90 with 16 MB of RAM.

I don't remember how it was back then, but now playing it on a modern computer, it just loads instantly. When I noticed how truly instant it was, I was so surprised that I just switched back and forth between loading two saves for a bit :-)