Is Messi the greatest footballer of all time?

When Barcelona's talisman Lionel Messi scored his second goal of the match against Real Betis in Seville on Sunday, a superbly placed shot off an Andres Iniesta backheel to the far corner of the net, he added yet another record to the growing list against his name. Messi overtook German centreforward Gerd 'Der Bomber' Mueller's 40-year-old mark of most goals in a calendar year. He now has 86 goals in 2012, as against 85 by Mueller in 1972 and 75 by Pele in 1958, and there are still some games to be played this year. Fans and a few experts are already suggesting that by the time Messi hangs up his boots, he will be acknowledged as the greatest ever to have played football. Do you agree? Or will some of the old favourites like Pele, Puskas, di Stefano, Beckenbauer, Cruyff and Maradona always have an edge?