I feel lucky that there are some fantastic puzzle cache makers around this area, and there are so many that I've REALLY enjoyed. Here are a few favorites:
Venonium 263 (GCT3RN) was really fun from start to finish, and utilized some nifty techniques that I haven't seen much in other caches. I did it on the night it launched, with 20-30 other people.
Counterparts (GCGQ42) and Double Agent (GCA8B3), both by Lamneth, are exquisitely clever caches with a fun theme and storyline. Highly recommended.
All Wet (GCPTR6) had a really tricky interweaving of a few different logic puzzles. It really challenged me, and finally getting it was a good feeling.
And lastly, Maya Silver: Tears Of The Moon (GCPKJW) was not much of a puzzle per se, but I really enjoyed it! It was merely the final cache in a series spread along a trail, and you needed to collect some info at each of the previous stages in order to get coordinates for the final stage. It was a beautiful hike, and the storyline associated with the caches was a lot of fun, so it gets a mention here.
I hope to hear about your favorite puzzle caches too! Thanks.