If I had to rank them...
1) Tom Brady
2) Kobe Bryant
3) Ronaldo
4) Usain Bolt
5) Serena Williams
6) Shaquille O'Neal
7) Roger Federer
8) Tiger Woods
9) Michael Phelps
10) Tim Duncan
11) Dominik Hasek
12) Zinedine Zidane
13) Lisa Leslie
14) LeBron James
15) Lionel Messi
16) Anderson Silva
17) Michael Jordan
18) Peyton Manning
19) Martin Brodeur
20) Derek Jeter
HM: Diana Taurasi, Floyd Mayweather Jr, Cristiano Ronaldo, Rafael Nadal, Michael Johnson, Ed Reed, Ladainian Tomlinson, Randy Moss, Nik Lidstrom, Manny Pacquiao, Sheryl Swoopes, Annika Sorenstam, Misty May Treanor and Kerri Walsh, Albert Pujols, Pavel Datsyuk, Alex Rodriguez, Justine Henin, Mariano Rivera, Venus Williams, Jerry Rice, Mario Lemieux, Sidney Crosby, Alex Ovechkin
My top 5 in the last 30 years would be Rice, Jordan, Gretzky, Brady, and Lemieux.