not all explicitly Hunter related and definitely not all the Addons I run, but maybe a couple less known
1.
Ammo-matique -Automatically switches arrows/bullets based on your target and location. I'm sure Deyami doesn't need to switch from Iceblade Arrow with his bank dedicated to housing 400k+ arrows, but for the rest of us, wasting 4 gold on battle grounds and trash seem a bit unnecessary.
2.
Skada -WOW.com just featured this addon and I must say that I didn't realize how much of a load Recount put on my CPU. Skada is more modular so you don't have to collect a bunch of other data you aren't using (like healing, etc...). Skada does calculate things a little differently so the numbers don't look exactly the same as Recount's, but probably close enough. Definitely made a noticeable difference during raiding (10 man anyway)....although I haven't tried on 25 man yet, but I have a benchmark of 2 fps from Thursday's raid to see if it helps.
3.
Quick Repair -Automatically repairs your gear and uses guild funds if available. Saves you a button click....yeah I'm a little on the lazy side.
4.
BuffEnough -This one is quite nice, just hover over the add-on window and it'll tell you what buffs you are missing and by who. Lot easier than looking at your buff bar and parsing icons to ensure they are all there.
anyway, just a couple that aren't quite as often mentioned PowerAuras, X-Perl, DBM, Omen, etc...
Edit:
5.
Range Display -Offers both a range meter for the # of yards you are away from your target and a nice display of the range of mouse over target.
