For me, Star Wars will always have the creative edge against the LotR movies because what you see in SW has gone straight from Lucas' mind to the big screen. It's like if Tolkien himself had been able to direct Lord of the Rings himself with all of today's technology.
That said, Return is a breathtaking motion picture. It has its flaws, and I'm sure it won't please the Tolkien fanatics because of all of the cuts, but it's a good movie nonetheless. I think Lynk has it right, LotR has the same novelty factor that SW had when it was brand-spanking new... but it's a close call. This is quite possibly the last George Lucas Star Wars movie ever, and every SW fan worth his or her stripes will see it at least once.
But regardless, money isn't the only judge of a movie's full worth. Just remember this: Empire has made the least of all of the SW movies, and yet is hailed as the best.