My wife and I are gadget junkies (suckers) and have purchased rulers/tools for many techniques just because they looked interesting. We have nearly all of Deb Tucker's tools and have used them all except Hunter's Star. We get the perfect units she promises with her tools every time. Hands down the Deb Tucker tools are my favorites.
We also love Gyleen Fitzgerald's Pineapple tool. We have made several blocks with it and have a ton of our scraps cut into 1.5" strips just waiting for their turn to be made into a quilt.
I recently used Julie Herman's Sidekick tool to make a diamond quilt. It just lacks the binding so I hope to post it soon. It isn't perfect, but overall I'm happy with the result. I'd like to try the tool with one of her patterns to see if I get better results. We have her Night Sky pattern so I hope to try that soon.
I have used the Creative Grids strip cutter ruler at a demo and found I didn't like it. I must be an oddball because I see so many of you love yours, along with the June Taylor fans. If I ever see another demo I'll have to try again.