Well, your build kinda depends on what you do most of the time.
I don't really off-heal, but i will throw heals in emergencies. Because I don't off-heal, I only put 5 points in holy to max divine strength. In the Prot Tree it is nice to get the extra 3% hit from precision, but if you are raiding or grouping a lot, the toughness does not need to be taken since you (hopefully) aren't getting hit hard enough to need it. If you ever mess around with a sword and board instead of a 2-hander (for soloing or whatever) then you might want to put the 5 points from Imp Devo Aura into Redoubt instead, but they both are pretty useless for a Ret since you usually won't be using a shield, and almost never will you use devotion aura (Sanctitiy Aura FTW); however, you gotta put those 5 points SOMEWHERE to get precision. I really wouldn't bother with toughness in my opinion.
In the Ret Tree, you are completely missing Fanatacism, which is a must. More criticals with your judgements is AWESOME, and the reduced threat is also a must. You aren't a Tank, so having the reduced threat just makes you able to do that much more damage without having aggro issues. I would also HIGHLY recommend maxing out sanctified seals. Also, in my opinion, parry is not important enough to put 5 points into. I would try a 5/8/48 build something like this:
http://www.wowhead.com/?talent=sxZxhZVfotocuiIst
(hopefully that link worked, and the improved devo aura could be switched to redoubt, but as I said, you shouldn't really need either of those talents other than to get 3 pts in precision...)
I think that you will find you do a LOT more damage that way and it won't gimp your surviveability at all due to the reduced threat/increased damage done. If you solo a lot, I guess the toughness would be nice, but other than that, the 5/8/48 build will probably make you happier as a DPS paladin.