Mk5 gets my vote. Following that the Leon FR/ Cupra if you can.
The only negative for me is that if I had a Mk5 GTI sitting in the drive, I'd rather sort it and take it on track than take the Mk3. In fact the same could be said really for any of the cars you have mentioned, with the exception being the Megane 225 as I really don't like them.
But in answer to your question, either the Mk5 or Leon.
