Paul is the latest in a line of comedies starring Nick Frost and Simon Pegg. It's a decent comedy that is never as funny as it's hilarious predecessors Shawn of the Dead or Hot Fuzz. I would suggest seeing it if you are a fan of this pair's specific brand of humor.
Jason Bateman delivers another comedic role that further elevates his status as one of the funniest actors working today. Seth Rogen's voice is perfect as the alien. Kristen Wiig is hilarious as usual. Pegg and Frost maintain the laughter throughout by re-establishing their status as a great comedic pairing.
If you're into buddy films and sci-fi, you'll definitely dig Paul. It's a well made comedy that offers some good laughs.