[opinion]
I personally prefer the Star Wars movies (minus Ewoks and Jar Jar Binks) because they feel more unique and original.
However, this is likely due to the fact that The Lord of The Rings suffers from a textbook case of the "Seinfeld is unfunny" trope.
http://tvtropes.org/pmwiki/pmwiki.php/M ... dIsUnfunny
The LOTR books were published in 1954 - 1955, and the latest incarnation of movie adaptions (Peter Jackson) started in 2001.
In the meantime, just about everything in the books has been exploited, adapted, reinterpreted etc., most famously by Gary Gygax in the Dungeons & Dragons franchise (DnD even had to change "hobbit" to halfling for copyright reasons").
For instance, Gandalf and Saruman are supposed to be über-powerful wizards, but in comparison with Elminister (a Gandalf clone) from The Forgotten Realms and Raistlin Majere from Dragonlance, they are incredibly weak. And orcs (pretty much invented by Tolkien), elves and dwarves are such core components in Fantasy nowadays that people would be surprised if they were absent.
For me, this makes the LOTR movies somewhat boring.
I think that Star Wars has kept more of its originality because (1) it is a more recent franchise and (2) because the aggressive trademark policy of LucasArts has kept tight reins on the key elements of the franchise: The Force and Lightsabers.
Of course, the original Star Wars movies could end up falling victim to the same trope as well. For instance, the lightsaber battles in the first 3 movies are quite mundane compared to Qui-Gon and Obi-Wan vs. Darth Maul and Joda vs. Dooku. Similarly, the most extravagant display of the Force in the original movies - Palpatine's lightning - is rather meh compared to displays of the Force in the Star Wars novels and games.
Oh, and Darth Vader is consistently rated as one of the greatest movie villains of all time, while LOTR seems to lack "really" iconic characters.
[/opinion]