Dungeoncrawl, Stone Soup is the best turn based rpg i've ever played. no plot, no graphics, just highly detailed combat. thats what i want in a turn based game; less filler, more goodies.
download a version with "tiles" in the name if you're not comfortable with completely text only mode. watch other people play, compare scores and strats, and survey class/race statistics at
http://crawl.akrasiac.org/
btw, there's no reverting to saved games; you can save and pick up from there later, but there is no going back in time. think hardcore diablo II.