Hit Rating, Expertise Rating, and Haste Rating are identical in their conversion ratios to a percentage value. Each has different benefits and drawbacks, however. Critical Strike Rating has a lower conversion ratio, but also has other benefits.
* Expertise more than doubles in value when you are attacking a target from the front. From behind, it has the same exact benefit as Hit. It has a hard cap at 5.6% (22.4 points/88 rating), after which it has absolutely no effect.
* For dual-wielders, Hit has maximum effect until your specials are capped (8.6%). Afterwards it's only as good as your ratio of white to yellow damage, up to the hard cap at 27.6%. It also improves on-hit based procs. The hit cap for single or 2-hand wielders is equal to the special cap.
* Haste only benefits white damage, so it basically starts out at the same value as post-special-cap Hit. It increases the rate of on-hit procs in exactly the same proportion as Hit.
* Crit doesn't have a cap or falloff point, making it worse than Hit/Expertise before the specials cap, but slightly better afterwards. Crit has no effect on DoTs/bleeds, but will benefit abilities that proc on critical hits (such as Deep Wounds).
Look, there are only so many ways I can explain this. Try this: go to Recount or WWS after a major fight and see how much of your damage was from melee and how much from your specials. That ratio is what you use to figure out how good Hit Rating and Haste Rating are compared to Critical Strike Rating.
Or, to put it another way, if you find an item with Expertise Rating, it's always better for you than the identical amount of Hit Rating, until you're Expertise capped. Once you are special capped with hit rating, Haste and Hit Rating are identical in value, while Critical Strike Rating is slightly better.