As I've alluded, Hot Tub Time Machine was a pretty cool original. It will never have been confused with great cinema, but it included time travel, pretty girls, one of my favorite living actors, John Cusack, and a fun and happy ending. No, not that kind of happy ending, although it did earn its "R" rating. Bear in mind, the sequel is almost never as good as the original - the only exception that comes to mind is Godfather II. Hot Tub Time Machine 2 is no an exception.
Unfortunately, John Cusack didn't participate in the sequel and Chevy Chase's character, the Hot Tub Repairman, makes only one scene. However, Lisa Loeb makes a cute cameo and Bianca Haase as Sophie, coat check girl and Jacob's future wife, is probably worth the price of the ticket.
Still, there are some pretty funny lines as well as time travel, pretty girls, and a sort of fun and happy ending. Just not that kind of happy ending.