I've been going broke for the last few years buying Gillette Sensor Excel blades. I am very happy with them. I started using them back when the original Sensor came out. Now that I have a goatee, and don't have as much facial area to shave, the blades last a little longer.
Maybe if I have a reason I will try this Mach 3 I've just read 20 posts about.
I've been using a Mach 3 since I was able to get it for free during the hot deals from drugstore.com and I'm not turning back to anything else. A little expensive, IMO, but I like it better than anything else I've used.