This film is about: fine wine, weddings, car crashes, relationships, broken noses, sex, and road trips. It’s an entertaining watch, and an emotional one. You can despise both the main characters and also admire them. Paul Giamatti in particular is good as the neurotic one of the pair.
Sideways is definite entertainment, and the two hours don’t lag. But, ultimately, there’s nothing very demanding for the viewer in it, so it’s probably a once-only deal.