You can rule out all the snipers that come with just a single elemental option, so no volcano or longbow.
I will say that despite statistics and firing range trials, the Cobra and Hawkeye are really good all-purpose snipers.
The White Death will remain in my backpack no matter what, but I'd say it's probably about the 4th or 5th best all around sniper. If you only need to snipe for a short bit of time and you know you can reload soon after it's perfect.
I'll need to put a disclaimer on the video that the best evil-smashed/infinite ammo glitched gun in without a doubt the white death.
The video is done guys... uploading to Youtube and I'll link you guys when it's done. Feel free to start posting suggestions for the next video. I was thinking handguns next, but let me know what you guys think.
XBL GT: Ki11er Six (ones instead of L's and a space between the two words) Various Borderlands 2 glitches: http://www.youtube.com/watch?v=ZgdactVBsYk