I have a few things that make me happy every time I use them. It's so nice to have stuff that works...
My beaded seat cover. Cut from a $7 Wal-Mart job, it's been on the bike for several years now. It turned long days from "Are-we-there-yet, can't-feel-my-legs, butt-cheeks-fell-off-in-Illinois" to "hey, that's not too bad." I need no powders, no fancy shorts, nothing else to have a happy bottom. Far and away the best value I've had on bike stuff.
Hot Grips. I got their variable PWM controller, too. Now, even on summer days and cool evenings, a little bit of electric comfort comes with me on every ride. Hands cold? Turn the knob. Ahhhh....
Aerostich Darien jacket. After years of leather and fussy raingear, I just don't worry about the weather anymore. Waterproof in hours of pounding, driving rain, it's nice to actually be confident in one's gear. The pants were a little disappointing, as the crotch will leak, though I've found a simple enough work around for that. It's pretty cool in the heat, too. If it's between 40 F and 90, I have my Darien on.
GIVI luggage. Yes, it's a cliche and common and ugly and boxy and all the rest. It's also waterproof, durable, practical and easy to use. It's luggage, not a fashion statement. And it carries my stuff well.
I haven't had it quite long enough to say for certain, but my Tipperary vest earned significant credibility when I took a header onto a bunch of sharp rocks a couple weeks ago. What do you know, pads that actually keep you from getting hurt! More detail here:
Lastly: LED flashlights and headlamps (for my head, not the front of the bike). I'm slowly replacing all my lightbulb flashlights with LED. Durable, lightweight and efficient, they're good lights.