browse through these strains all are made with top genetics, cardiac arrest seems like its got ridiculous potency but i personally don't like the sound of it lol
http://www.potpimp.com/forum/viewforum.php?f=53
also on that site anything by og raskal will be dank not sure if there are any going right now but he's working of some new crosses think with kyle kushman's strawberry cough, i haven't smoked it personally, but i don't think its top for raw potency but sounds a very nice smoke and is definately on my list. thing is though he'll be crossing it with the white and maybe og kush (fire cut) which will be right up there so definately worth checking it out. his gear always moves fast.
http://www.potpimp.com/forum/viewforum.php?f=55
or check out the outlaw genetics, he's not at potpimp yet but is available at breedbay, maybe look into the east coast purple diesel, that looks amazing
http://www.breedbay.co.uk/auction/categories.php?parent=1966
maybe something from subcool like jack the ripper
http://www.breedbay.co.uk/auction/categories.php?category=Beans&parent=315
all of these are highly recommended, while i have never actually smoked any of these strains these are the breeders that i am running this time round after lots of looking around, apart from outlaw i don't have any of his wish i did though
good luck finding your strain i'd say look for a good breeder(s) and then choose something you like