My personal opinion is OCZ. I am using it in my build and it has worked amazingly well. Some people prefer Kingston, while others will stand behind Crucial or Corsair. I think it is personal preference. I would say that if you stay with one of the aforementioned, that you will be very happy.
I use corsair. I would recomend that you check into the manufacturers warranty. If the memory comes with a lifetime warranty you can hardly go wrong. Check to see what is compatible with your motherboard. Not all dimms work with all motherboards. You can usually find this information online through your motherboard manufacturer.Also, check out all comments about the memory brand you wish to purchase. Maybe so have bad customer service/RMA service. Do your homework and dont get inpatient.
Crucial IMHO is the best. Corsair and OCZ are pretty good too. I'm not too sure about Kingston, but if you're not OCing then it should be fine. Also my motherboard is more stable than any Intel! AND it can overclock.