Nikon SLR Cameras

What is better the sony slt-a37 or nikon d3100?

Sim
Sim

What is better the sony slt-a37 or nikon d3100?

Andrew
Andrew

The one that feels better in your hands.

G hound
G hound

That can only be answered if the context of how you want to use the cameras is outlined and whether you have access to legacy lenses for either.
Sony no longer make a small form factor DSLR and the A37 and A57 have been replaced by the A58, which is a dumbed down A57. (A57 would be the one to get if you're quick before they are all gone).