don't know if it exists- unless you get that lucky pheno, which you could get w/ bagseed... man I look for the OVERALL- price, yield, flower time, ease of growth, good enough stone, etc... AK-47, Nebula, SAGE, are all great choices then... Nebula may be the BEST choice in that way- good yield, quick flower, easy to grow, potent, great taste and smell, and cheap- 5 fem beans for about $70, 10 fem beans for about $115 or $120( I believe )...if you keep looking for that Holy Grail of pot, well, just like the "real" Holy Grail, you may never find it...
Of course, all this assumes that you're looking for something other than just Nirvana's seeds...
Of course, all this assumes that you're looking for something other than just Nirvana's seeds...