This was recently discussed on sky sports after England beat South Africa in the Boxing day test match.
This was Sir Ian Botham's opinion
Beefy's XI
1) Graeme Smith (SA)
2) Virender Sehwag (Ind)
3) Ricky Ponting (Aus)
4) Sachin Tendulkar (Ind)
5) Brian Lara (WI)
6) Jacques Kallis (SA)
7) Adam Gilchrist (wk) (Aus)
8) Shaun Pollock (SA)
9) Shane Warne (c) (Aus)
10) Allan Donald (SA)
11) Glenn McGrath (Aus)

more opinions can be found here: http://www.skysports.com/story/0,19528,12172_5812308,00.html

however, my test team of the decade would be
1) Matthew Hayden
2) Graeme Smith
3) Ricky Ponting
4) Sachin Tendulkar
5) Brian Lara
6) Adam Gilchrist
7) Andrew Flintoff
8) Dwayne Bravo
9) Shane Bond
10) Anil Kumble
11) Shoaib Akhtar

cricket on tv should be banned it is the most boring game ever invented,in fact whoever it was must have been crowned the king of bores.i really do not know how anyone can watch it hour after hour day after day and it does go on for days,if anyone out there could explain that to me i would be very grateful thanks