My favorite is DNA's OG #18 crossed with Skunk for the large yields and the pain relief properties.
For regular OG Kush, I'm not sorry to say I've found a new love: Riot Seeds.
Riot is pricey but their OG is some of the best I've smoked. That OG high is not really describable, it just is, kinda soaring but squinty eyed at the same time? You just know it's real OG if you've had experience with it. Riot has an original OG Kush (Gangster S1) and an OG Kush called Muerte OG. My pal grew out the original OG (S1) and it was a tricky grow for him even though he's been doing it about 4 years. The yields were decent but not out of this world, but the nugs were really gorgeous with nearly perfect bag appeal. Put it above the top shelf!