While I like the inquiry to this question on possible matches for the flash, I have some reservations on the choices that were pointed out. First of all, superman by far, is not on the same level of speed as the flash... That was shown in Smallville and other media (albeit, I know Smallville did not stick entirely to the way the comics originally set things up.) Second, and most importantly, (at least to my knowledge) there has been no recorded time in which Superman ran or flew so fast that he was able to break the time space barrier, which the flash has proven he was able to do. With the other characters they are all in a different universe so I don't think it is a fair comparison. Nonetheless, in the case of quicksilver he had to be augmented to reach the speed he attained. The flash reached his top recorded speed by sheer force of will. So I think that tops quicksilver. The other two I don't really know their back stories as readily, thus I am not going to weight in on the subject; but at least for the first two, I don't think it is a contest. Flash is on top.