Is this your only car?
Do you need a practical car?
If it is a second car or a weekend only car. Ask yourself what cars you've always wanted and what you want to use the car for.
I'm going to assume based on the thread so far that you're after "something special" and practicality isn't important.
If you want something truly special, then don't go based on specification, go on how it makes you feel. Stats don't necessarily equal enjoyment.
I don't mean to single out the Megane here, and to be honest a fast VAG model is probably the best example of this, but no one has suggested one of those! but it's a good example of picking a car based on performance stat top trumps.
Generally, owners also seem especially blind to this and often suggest their own car no matter the OPs circumstances.
An RS Megane is still a Megane and while technically brilliant to drive etc, it's ultimately a practical family car with better performance. I get it, I've driven a few RS models and they're brilliant, but their strength and weakness is that at the end of the day they're a Clio/Megane. If you need a practical car and this is your only car, then hot hatches and fast estates are great. But IMO don't really fit the OPs brief. They're not special enough unless you throw nostalgia or vastly different engineering in the mix.
Unless it's always been you dream car or you have an emotional attachment to it, you're never going to consider a Megane special and it's never going to make you smile just looking at it or turn around as you walk away for a second glance. A nurburgring lap time is not a good indicator of the best car for most people.
As an example to the OP - if you don't like the TT, then the TTRS might be technically brilliant, but do you desire one? It sounds like you're almost trying to convince yourself that it's a good choice.
If a Mustang V8 is your dream car, I'd start with a test-drive of that so you have something to measure the other cars against.
Remember if the Mustang V8 makes you smile just sitting in it in the car park or driving it at 30mph, but you need to drive the alternative flat out to enjoy it, you'll probably get more enjoyment from the Mustang as how often do you drive flat out?