I have Geissele SSA Trigger in one lower and a LWRC Enchancedd Trigger in another. I love the SSA, LWRC is just a slightly improved mil-spec trigger really. SSA are about $160-180. I've been itching to get one of Geissele's New Super Dynamic triggers. Can't go wrong with any Geissele trigger.
Just dropped a Timney 3# single stage in mine and love it compared to factory.
If you don't mind putting one together, the JP fire-control group with the speed hammer is a good choice. I have one in my 5.56 gun and is very nice. Breaks right at 3.25# and no creep.
In my 6.8 I have a Timney drop in assembly. It too is great, breaking consistently at a hair under 3#.
Both are single stage.
I am in the process of building a 6X45 and I am going to give Bill Springfield a chance. I have a PSA fire control group that came with the LPK that I built my 5.56 gun with. I am going to send it to him to have him do his 3# work on. I will test it out on the 6X45. If it is good as everyone claims, it will stay there. If not, I will change it out the the JP and it can live in the 5.56 as I don't need that one to do precision work.
I like the Wilson Combat 3G. I am sure the other triggers recommended are fine too. I like the 3G because it has no creep, no grit and a positive reset, just drop it in and watch your groups shrink.
US Army Retired
I have two McCormicks, one Wilson and a Springfield trigger job. While not the cheapest, for hunting I prefer the first two.
'67 Tonkin Gulf Yacht Club, "Big Mothers"
I got to try a cousins custom AR a couple of weeks ago, it had a Rock River National Match two stage trigger in it - I was quite impressed. I think this trigger will be in my future for my Barrett REC7 in 6.8, the factory trigger in it is pretty bad.
The Rock River had a reasonable amount of take-up but a very nice crisp pull ofter that. I think it would be an excellent choice for a multi-purpose AR. For a bench only gun I could see going to a dedicated single stage trigger, but not for 90% of users.
I have a couple RRA NM triggers and do like them. For a simple GIvsingle stage, the ALG ACT triggers are good but heavy.
You can't go wrong with an RRA 2 stage post break-in/polish for the price.
I owned a CMC drop in and was unimpressed, quite a bit of creep for the price unless you're hammering the trigger and don't feel it. I replaced it with a Geissele SSA-E, which I will use for every future build of my own. (I am indifferent to 2 stage or single stage.)