Dollar stores are always the best for these kinda toys. Before it closed down, the one around the corner from our apartment was selling Chinese knock-offs of the Incredible Hulk. His face looked like an Asian Frankenstein, he was made out of the cheapest plastic possible, his knees bent but his elbows didn't, and for absolutely no reason he came with a little red light in his chest that would turn out if you pushed a button in his back. I bought several and gave some to my comic geek friends. Sadly, the lights on the two I kept both died within a week and there's no where to replace the batteries...
My all time favorite dollar store toy has to be a collection of cheaply made (shock, awe, surprise) soldier figures, but they were zombie soldiers so they had stuff like exposed brains, chunks blown off their limbs, and not-so-internal organs. I only bought the exposed brain one, then when I went back they were all sold out. I've still got him boxed up somewhere around here...