I finally made it to Muy Macho after reading about it on the board for quite a while.
My girlfriend and I only had tacos (3 apiece), so I can't speak for the rest of the menu, but I haven't had better tacos in Seattle. In fact, the only better tacos I've had period are the ones at La Tarasca in Centralia.
We tried the carnitas, al pastor, pollo, carne asada...I think that was all we managed to try. Generally I avoid carne asada tacos, because most of the ones I've had are either boring or gristly, but my girlfriend ordered one and I had a taste. The beef was moist and juicy and just bursting with well-seasoned yumminess. I was astonished, I'd completely given up on carne asada (at least in taco form).
Everything was delicious--apologies for not giving further detail, it was a few weeks ago that we went and I can't remember much beyond a sense of complete taco bliss. I usually end up drowning my food in salsa because I take any possible excuse I get to eat a bunch of salsa, but the tacos were so good I didn't want to cover up the flavor. The salsa was good, too--pretty similar selection to what you'd see at Guaymas.
We were starving when we arrived, so we got chips and salsa to munch on while we waited. These came with a side of refried beans that I'm fairly sure were made with lard. Very nice to see the real item.
I'm also hoping to make it to El Vagre sometime soon, it sounds quite promising. Thanks much to those on the board who have mentioned Muy Macho and the overlooked jewels of South Park.