Who was more dominant? Sampras at Wimbledon or Nadal at Roland Garros?

Nadal has now won 7 French Open titles, same as Pete at Wimbledon.

They both seemed to have at least 1 slam a year in their pockets each year, and have never lost a final at their tournament, suggesting once they got to that stage they were as close to unbeatable as it got. Who would you have play for your life? Sampras at Wimbledon or Nadal at Roland Garros?

Nadal, without a doubt. Just compare Sampras five-setters at W vs Nadal five-setters at RG (1 v Isner).

Nadal at Roland Garros, Sampras lost to Fed at Wimbledon, and if not for a close Wimbledon 2008 Fed would have been 7 in a row now, in comparison Rafa looked not just invincible but scary for the most part of the tournament in many years.

Pete has lost in Wimbledon many times to many big hitters like Goran. Richard Krajicek etc,. but Rafa never lost in RG to another clay courter, I consider Robin as a hardcourt specialist.

Beating Nadal at RG is the biggest privilege.

It's Nadal at RG.

Thus far Nadal has compiled a 52-1 record, Sampras's record at Wimbledon was 63-7. Nadal won at his first attempt, he has won two without losing a set (2008 and 2010), and he has faced only one five-set match. Sampras cannot match any of those statistics overall.

You could ask who was most dominant during his best years and there is much less to chose between Sampras's 1993-2000 and Nadal's 2005-2012. In fact, given the crap-shoot element of grass-court tennis during the 1990's Sampras's ability to win out is arguably the more impressive - but that is a different question and we don't know whether Nadal will win or make the final next year and put even that question beyond doubt.

I think it is too early to tell given Nadal is still in his pomp.

I would've said Sampras last year, but given that Nadal has yet to drop a final at RG and his current record that all stats point to him. Next year he has every chance of eclipsing Sampras's form on Grass.

I think Nadal has the better record, but personally I think Sampras was more impressive as he had genuine threats, and with the fast conditions he could have easily lost in 3 tiebreaks, at the French Nadal has time to figure out what to do

Agree, we've not seen Nadal in decline yet, though I think we will soon enough given his age.
This match has taken something more out of him, I think.