On my stealth class I run Ghost Pro, Slight of hand Pro, and Hacker Pro. On my run class I run Flack Pro, Slight of Hand Pro, and Marathon Pro. I have a Hardline Pro class I switch to if I want to change a care package as well.
As a rule, I usually use Ghost, Warlord, and Hacker or Ninja.
I've usually got a class set up with Flak Jacket in case I run into an entire team of tubers, and one with Lightweight, Sleight of Hand, and Marathon if I feel like going bersercker.