Definitely wait til the 1080 or the 1070 (if you're willing to wait about a month for that one) to come out. They are as good, or they say is better, than a Titan for like $400-$500 less. These two cards should be better, but I've only seen the graphs where they compare the cards to a 980Ti. Again, it does depend on your budget though, so the price for older cards will definitely go down. I bought a 970 two months ago ;~; but it's still a pretty sweet card and can run alot of the newer games very well.
Like Pan said, it's good to use a power calculator and I bet you could find a 80+ (bronze, silver, or gold) with 600+ watts for a reasonable price. PSUs aren't that expensive.