1. Nadal - 17 strong era slams, Olympics gold, La Undecima, 9-3 and 9-5 in slams vs his 2 biggest rivals, at least 2 slams on each surface, 10 consecutive years with a slam title, masters 1000 titles record, 4 davis cups, has never broken a racket, etc. etc.
2. Federer - 20 slams but at least 10 of them in a weak transitional era, Olympics silver, 3-9 and 6-9 in slams vs his 2 biggest rivals, only 1 clay slam out of 20 total, many weeks at no.1 (but a lot when Nadal was injured), consecutive SF record, wtf titles
3. Djokovic - 14 slams, Olympics bronze, 5-9 and 9-6 in slams vs his 2 biggest rivals, doesn't have much over Federer who basically covers him everywhere
4. Sampras - 14 slams, no clay slam and therefore no career slam, but clearly dominant in his era
5. Borg - 11 slams, great career but not enough slams to rank higher
6. Laver - 11 slams, great career but dinosaur era with much less competition, he's overall overrated but deserves to be in the Top 10 due to his calendar grandslam
7. Lendl
8. Connors
9. Agassi
10. McEnroe
I think Mac should be above Agassi. Andre was never really a dominant #1. Mac was. Sure, Andre has an extra major but Mac rarely bothered with the AO and has a better all round resume outside that.