Djokovic - Madrid SF 2009/USO 2010 F/Olypmics 2008 SF. Pretty sure these are the most heartbreaking losses for Nole.
Murray - Wimbledon 2012 probably.
Federer - Too many. I'll let his fans decide.
Nadal - Probably AO 2012 final. Wimbly 2007 final too maybe (I heard he cried after that match. Not sure.) Let's see what Rafa fans say.
Del Potro - RG 2009 SF probably. He cried after that match.
Ferrer - I don't know. Maybe Mugami 2013 F.
Berdych - ????? Not sure I can call his loss in Wimbly final the most heartbreaking in his career. He was so shit in that match.
Tsonga - probably RG 2012 QF.
Tipsarevic - USO 2012 QF.
Gasquet - ????
Wawrinka - Surely AO 2013 4th round.
let's make a list of the top 50. Could you guys help me? you can only pick 3 losses for each player.
For Del Potro it was definitely the Olympic SF last year.
Cilic - THE CHOKE
Berdych - I'd go with the Madrid final last year, he was the best player all week and choked a pretty winnable final against Federer. Berdych generally doesn't have that many gut wrenching losses though, or at least he makes sure he loses big matches in clear fashion I suppose.
Soderling - WTF 2009 semis probably
Monfils - Paris 2009 final