Pressure Washing the Deck

The Good Wife suggested that we clean the deck and then put a sealer/stain on it.  It has been a long process, partly because there hasn't been that sense of urgency.  We are borrowing a pressure washer from some friends, so there isn't the urgency of needing to get the rental back to the shop, so we have to get it done this weekend.  That's why it has been more than a month since we started and we still aren't done.

At first I didn't think it needed to be washed, but after starting, the Good Wife was right.  It was horrible.

The dark portion is the deck before washing.  The wood colored decking is after washing.  Don't ask me why I started the deck on the left and then decided to do one of the benches from the right to left.  I'm not even sure why that happened.  It may have been that I was trying to show the difference between washed and unwashed.  Regardless, it was hard to argue it didn't need to be washed after the project was started.

We're not done yet.  All the deck is pressure washed, and the railings from the deck side are completed.  All that is left is the railings from the outside and the framing around the outside.  It is just going to take a good day of work to get it done.  And now that the cooler temperatures are coming, we better get it done quick so we can get it coated before the winter weather comes and the sealant won't cure.

The question now is what sealant should we use?  We like the wood color of the deck, so we don't want to use a stain that is going to change the color of the wood, but we want it to be weather sealed.  And I definitely don't want to be doing this again next year, so I want something that is going to last.  If anyone has any suggestions or had good experience with a particular brand, please let us know.