My preference is Works Shocks due to their reputation in the competition area, their shocks are custom made for you and your riding style(s), plus they are rebuildable unlike some shocks.
Of course it depends what you are looking for; I ride 2 up 95% of the time, I like the convenience of ARS with a dual rate spring for the great weight I am putting on the bike with my ability to simply switch from 2 up to solo, to aggressive by flipping a lever on each shock. The pair was a little less than $700.
I personally didn't gamble the O shocks when I read on this board $1000. shocks were leaking at 20000 miles and it cost $250. for a rebuild. Call me cheap, frugal whatever: $1250. for 18 months documented by by at least 2 members on this Board is unacceptable in my eyes if you consider the shocks actual monthly cost for the 18 month period was $69.44. Therefore, I personally question either the design with regard to Harleys and or quality control. The O shocks have been running on the Euro bike for years without mandating rebuilds at 20k.
The only time I paid for a rebuild was when the load changed by 80 lbs. and it cost me $60.per shock at 43000 miles and the shocks were not leaking (pistons, seals did their job even-though they were over loaded).
However, whatever manufacturer you call; see what they can do for you, not what you can do for them.
Again, this is only my opinion