I guess it depends on how you define "trophy". Any sheep tag will provide a high opportunity for success that will put a trophy on your wall like no other. The biggest rams, without a doubt however, have been coming out of the Swakane unit. The big rams can be tough to find and you would need to plan for an extended hunt with lots of scouting. The potential for a 170+ California Bighorn is good though.
Most of the other units provide good looking rams but just dont score as high. Cleman and Quilomene are good choices as is Lincoln (although the private land there can cause some challenges). The wild card this year is the new hunt which is in the Tieton unit. That is a transplanted herd started with some Cleman and Lincoln sheep. In about 2000, some sheep from the John Day River herd in Oregon were released in there as well. The John Day sheep are world class California Bighorns with several in the last few years breaking 180. There will be two tags in the Tieton this year.
For anyone wondering, we are getting very close to re-opening hunting on Rocky Mountain bighorns in the Blue Mountains. I will share the status of that another day as I am getting a little long winded here!
Glen