When Michaelangelo finds a genie in an old copper lamp, the fearsome four are whisked back in time to the Wild West -- for a showdown with three gunslingers.
I read this back when I was in elementary school so of course then I really loved it I was a huge ninja turtles fan still lamb but I was even bigger back then so this really resonated with me.
This is what it meant to be a kid in the late 80s/early 90s: Teenage Mutant Ninja Turtles and cowboys. I think it took me a month to read the whole book (hey, it was a tyring activity - and I had other things to do, like eating plasticine and baking mud cakes), but I do remember loving it.
When I was seven years old, the Ninja Turtles were whom I wanted to grow up to be. Sadly, twenty years later I'm nowhere near being a mutant turtle with considerable skills in martial arts, but I guess at least I'm not living in a sewer. Small victories, I suppose.