Note: I'm not saying these are super awesome, just some that I use.
Enjoy/flame at your will.
/cast [stance:0] backstab
/cast [stance:1/2/3] Ambush
Ambush when Stealthed/Vanished/Dancing. Backstab out of stealth.
/cast [mod:shift, @focus] Blind; Blind
Blinds target, or Blind Focus with Shift. I use this with Gouge, Kick, Sap, and Shadowstep as well.
Cheap Shot + DR Timer
#showtooltip Cheap Shot
/cast Cheap Shot
I'm a minimalist and I don't use a lot of addons. This macro makes a Stopwatch Timer that counts down. Lets me know when it's safe to Kidney Shot. As an added bonus, it dings when it hits zero - so I don't really even have to look at it.
Kidney Shot + DR Timer
#showtooltip Kidney Shot
/cast Kidney Shot
Same deal, only with Kidney.
/use [nostealth, nomod] 13
/cast [mod:shift]Will of the Forsaken
Uses your top trinket slot, or racial with Shift. I have it bound to Q, so it's nice for me because it won't work in stealth if I accidentally bump it. I don't include Stance:3 in case I'm cc'd while Dancing.
/cast [stance:0] Evasion
Same idea as the trinket macro. Won't let me use Evasion while Stealthed so I can't knock myself out accidentally.
/focus[@mouseover, harm, nodead]
Clears my focus if it's dead, or if I have a friendly set as my focus. Otherwise Focuses harmful targets on mouseover.
/cast [stance:0] Hemorrhage
Garrote in stealth, Hemo out of stealth. I have a tendency to keep similar abilities on the same keybinds. This is bound to 2. Gouge/Sap to 1. Ambush/Backstab to 3, etc. I have a Mutilate/Ambush version for PvE as well.
/castsequence [@focus, mod:shift][@target, nomod] reset=20 Redirect, Kidney Shot
Lets me double tap to Redirect and Kidney Shot my current target, or my focus if I hold Shift.
/cast [nostealth] !Stealth
/cast [mod:shift, @focus] Sap; Sap
I use this to double tap Stealth -> Sap for when I'm able to drop combat. Holding Shift lets me Sap my Focus in case there are two targets nearby and I need to prioritize.
/cast [@focus, help, nodead] Tricks of the Trade; [@targettarget, help, nodead] Tricks of the Trade; Tricks of the Trade
Standard Tricks macro. Casts on friendly Focus if set. If not it looks to my target's target. Otherwise it casts Tricks on my current friendly target.
/cast [nocombat] !Stealth
/cast [combat] Vanish
This is just a little macro for insurance, in case I drop combat as I'm about to Vanish and don't realize it. It'll cast Stealth out of combat, or Vanish while in combat.
Edited for clarity.