I'm going to do this from around 1990 onwards. In no particular order:
Freddie Flintoff- Purely for the way he lifted the country with those mammoth displays in the 2005 ashes. How good could he have been if injuries hadn't ruined his career.
Shane Warne - Superb bowler and a hell of a character! His performances in 2005 added to what is the greatest test series I have ever seen.
Roy Keane - A players player. Led the most succesful team of the 90 and noughties to success with battling displays. His performance against Juve in 1999 was all the more incredible that he knew he wouldn't take part in the final.
Tom Brady - Top class NFL performer for the last 10 years. Will walk into the hall of fame with ease having broke numerous records.
Cristiano Ronaldo - Love him or hate him he is, in my opinion, the best footballer we have seen on these shores. Will go on to become one of the greatest of all time.
Honourable mentions to Murali, Beckham, Maradona, Messi and Tyson. O'Sullivan and Taylor would be up there but if you can play it it in a pub it doesn't really feel like a sport to me.
Will have missed out a ton of people and will probably change all of these at a later date!