Thats pretty relative tho. Theres alot mice (mouses or grammar nazis) that are better than infamous steelseries ones but nobody gets them because their lack of advertisment etc. Some pros are forced to play with sponsored ones because its in their contract blabla, some use what they like. Personally if I'd suggest you a mouse it would be a Zowie mouse, Razer DA2013 (which I heard is pretty good) or Logitech g400s (which isnt that expensive, has a great old 518-ish shape and its super durable). NEVER go for steelseries unless you wanna deal with bugs and shit.
edit: anyway if you want to get zowie ones
ZOWIE EC1 - most likely same as IE 3.0
ZOWIE EC2 - similiar to IE 1.1
ZOWIE AM - pretty much same as IE 1.1
ZOWIE FK - reminds me alot of a mix of razer krait/copperhead and zowie AM
2014-03-20 12:20