Zowie FK if you can get it. It's basically an upgrade of the IME 3.0, one of the best mice ever made. The sensor is probably the best ever made and same as the IME 3.0 and WMO 1.1 (STMicroelectronics OS MLT 04 with a perfect control speed of 1 m/s if I remember correctly).
Before the days of Razer/Steel series, IME 3.0 and the WMO 1.1 were the kings of mice, alongside Logitech mice like the m500 and mx518. If the professional players weren't bound by contract to use Razer or steel series, I can guarantee that many of them will choose these mice instead.
But Razer and Steel series make good mice as well, so if you get that, it wouldn't be a bad choice either
BTW, try not to go for laser sensor mice because they tend to have negative acceleration and sometimes glitch out.