I honestly cannot get into any Rat clones I've tried. They all seem to lack something that the original has. The filter on the original is much better than any clone I've tried and that's a crucial element for me with bass. The second best would be the Volt Thrower but I just don't need all those clipping options personally.
Some of the others named didn't meet needs for low end but most are fun regardless. The Rat isn't my favorite filter but it's good for certain situations. I've found it works amazing when recording.