These are probably the best diablo-like I've ever played (until now). If you like the genre, you won't be disappointed. especially the #2 which add nice possibilities : a couple of side quests specific to each character, the possibility to create your own magic items, specific skills for each character. Definitely has some replayability. I found "normal" mode to be quite easy, if you are experienced with this kind of games you can begin with difficult mode.
Oh, and BGDA1 sorceress is very ... sexy. Just discard her armor and, errr...
Others with a refined RPG palate tend to turn up their nose at those types of games. I think they are simple, old fashioned good fun. Kind of like a jazzier version of Gauntlet. Why not. They are fun to play with your less than adroit girlfriend. She even figured out how to be the cleric for the second one.