Mine is "Biker Mice From Mars".
It had similar elements: 3 humanoid brothers
who are mice instead of turtles... and bikers instead of ninjas...
who eat a certain kind of junk food for every meal, hot dogs instead of pizza. (I couldn't find any google pics of them eating hot dogs)
And they hang out with a cute, sassy human girl
And they save the world from evil aliens
who have lots of sidekicks
And there were toys and video games of all this stuff
It even shared at least one of the voice actors from TMNT, Rob Paulsen, none other than Raph in the original series and Don in the 2012 series. Oh, and it had this guy
from 90210 as one of the 3 main mice, and all the other main 90210 guys, as voices throughout the series.
All-in-all it's not as good as Teenage Mutant Ninja (Hero) Turtles, but I still enjoyed watching it with my lil' brother and get nostalgic for it every now and again.
That's my favorite TMNT ripoff! What's yours?
They did another updated version in 2003, but I didn't see any of it