Your most important RAs are Purge 2, IP 2, LW 1, and MoS 3. All hunters should have these RAs.
After you have the 4 RAs listed above, options vary with spec.
Melee hunter passives include Aug Str, MoP, Toughness.
Bow hunters will want higher MoS (5--4 only if you can't afford 5), Aug Dex (only enough to cap dps—see “Maxing Archery DPS” entry), Falcon’s Eye. Bow hunters may prefer First Aid to IP.
Other generally useful but less important RAs include toughness, Aug Con, first aid, and Wild Minion.