If it were me SG. SS make so many bats sure if you could pick them by hand I'm sure enough could find a bargain.
Don't know much about A2.
Folks can correct me if I'm wrong - but I
think I read somewhere that SG pump out the largest numbers.
A2 are interesting - they seem to pump out pretty darn high quality goods - craftsmanship looks good. I've never seen one in the flesh though...
If you're looking to spend a fair chunk on an SS - I wouldn't look further than the SS Maximus range, they've increased their Players bats to 77k INR, which is pretty nuts, and have introduced a 150k INR bat. From my experience, their LE/Maximus grade is pretty much on par with their Players.
The SG RP Icon and KLR Icon ranges are pretty darn similar to the Players shapes, so can be a good shout for a budget option.
If you're looking for Value for Money, I would guess that A2 might offer the best - they don't have so many sponsored players to feed, and make in a more limited number, so probably have a better control of quality. (I haven't seen any in person to judge) If you can visit a retailer, there are some Butterfly gems that SS seem to make.