HOMM3 is really fun and can burn days and days and days in it. Pity I never beat the official campaigns as some are tough for me. I always wanted to build everything, have a giant army and then make advances but some missions don't really allow that.

(Had to think for a bit on this one. Heroes Of Might and Magic 3.)

I agree it's a good game. I had similar issues so it was always custom maps and campaigns for me.