On all my vehicles I normally use OEM.
Why? Look at the facts normally before you have to change them the vehicles got at least 70-80k on it, isnt that kind of mileage a good enough recomendation to use the same brand again? I dont know of many aftermarket thet can advertise that kind of longevity, at least not truthfully.
On all of the different cars that I've owned, I've only had 1 that we ever bought the plugs and wires from the factory from and that is our '91 Nissan 300ZX (my toy). Only because we tried out two different sets of the plugs and wires from auto part stores and they were crap. The ones from Nissan worked awesome and ended up costing us less in the long run.
Problem with Toyota OEM is not that easily available anywhere. It is only available from the dealers. So once, I have to change something, definitely, the replacement is an aftermarket.
If I have the extra cash.. then I would go for a bit pricier aftermarkets.. I'm brand conscious, and I always go for those who have proven their worth!