I've had a couple of the more elaborate, big name units, (Crank Bros? Topeak? I forget) but now I just have 3 old-school Park multi-tools, that I've had for decades now. I don't even know what they're called, but they're the ones that look kinda like a big blue Boy Scout knife. Two just have Allens, but one has a Phillips and a flat-head in it, too. I get tons of use out of those things, and never go on a ride without one.