If you want to enjoy these movies tell your GF to get out, go visit her mother or something. Then get some beer some eats and maybe a few buds to come over and yell at the movie with you.
Picked up the new one from Redbox tonight and was quite entertained. Not better than the original, but definitely on the same level.
Actually my GF turned me on to the original, she could probably recite the whole movie.