Could you also give reasons for why you rank them that way? Achievements on clay etc?
I will try and do a rough breakdown on my thinking:
1. Nadal- 9 RG titles, dominance on clay beyond any other.
2. Borg- 6 RG titles, comparable dominance at his peak to Nadal on clay actually. IMO higher level of play on clay than Nadal, but simply not enough longevity or achievements relative to be over Nadal.
3. Lendl- 3 RG titles like Wilander and Kuerten but easily beats both in overall clay achievements, and easily bests Wilander anyway in level of play too.
4. Kuerten- In achievements overall is behind Wilander, but both have 3 RG titles, and personally I think Kuerten at his best would wreck Wilander.
5. Wilander
6. Vilas- 2 clay titles out of basically 1.2 clay slams per year (U.S Open was on clay but only for 3 years), 7 Clay Masters, and 40+ clay titles. When he wasn't playing Borg who was a nightmare match up for him was scary great on clay.
7. Djokovic- 8 Career Masters, including 4 Rome titles, and now with the RG title and all his other finals there has to be over all other 1 time RG winners, and some of the 2 RG winners too.
8. Courier- giving him large credit for dominating the 92 RG event with a super tough draw full of formidable clay courters, winning back to back RG titles, and very nearly doing the 3 peat. Was considered best clay courter in the world from 91-93, despite the upset loss in the 93 RG final.
9. Muster- As mentioned giving him lots of credit for his massive clay title count and general 95-96 dominance on clay.
10. Bruguera- like Courier defended his RG title, and has many other clay titles and clay success. These last 3 could be argued in any order really. He was owned badly by Muster, and Muster was owned badly by Courier (Bruguera did well vs Courier but hardly owned him) so that impacted my order of those three as well.