If we're talking reliability:
The best: My 1995 Laguna RXE 2.0. It suffered from a battery discharge problem that meant it wouldn't start if left parked for over a week, but that was preditable and so not a problem. It never left me stranded on the motorway, apart from twice: Once due to a water leak caused by motorway debris hitting the pump, and again when the dealer failed to fix it properly, and told me that the unusually high temperature readings I was getting were 'nothing to worry about.' It dropped its back box onto the tarmac at 80mph on the motorway once too, but that's just a Renault thing, apparently.
The worst, I'm sorry to say, has to be this one. I'll only list the serious stuff, but in 80K miles, I've had:
* Three major
leaks (one of which ruined a path we'd spent over two grand having re-laid only a year or so earlier. One was so bad I could smell it - when I told the dealer, they reckoned it was probably a plastic bag wrapped around the exhaust and not to worry. When I finally took it in for them to look at, they told me it was a fire hazard and too dangerous for them to let me have it back until it was fixed.
* Power steering rack and pump failure, which between them took nearly 3 weeks to fix, largely because of Renault insisting that the dealer test the steering rack with a piece of equipment that they didn't have.
* Starter motor jammed and engine intake manifold failed, both on the same day.
* Numerous engine sensor faults (resulting in the voice warning giving a fuel injection and ESP fault for some reason.)
* Intermittent fault on no.2 injector causing severe loss of power.
* A new gearbox at 70K. As far as I can work out, not due to wear and tear, but because the latest leak was from the gearbox.
And that's just the stuff I can remember right now. Give me time to think and I'm sure I can come up with more.
Remind me. Why have I ordered another one?