I second chesstempo.com. It's an amazing site!
Best Chess Tactics book for 1500 player?

I'll get you the link to Coach Heisman's recommended book list:
http://danheisman.home.comcast.net/~danheisman/Events_Books/General_Book_Guide.htm#DvoretskyTacticsSet

what's wrong with chesstempo.com?
It's great for pattern recognition but for more involved sacrifices and combinations you'll need a good book. I'd recommend Muller's (of Secrets of Pawn Endings and Fundamental Chess Endings fame) Magic of Chess Tactics for 1500. A book would give context to the tactics and help bring the relevent positions up on the board.
Hi, I would greatly appreciate it if some knowledgeable players can write in and tell me what would be the best tactics book for me to increase my rating. I already own Seirawan's winning chess tactics and Judit Polgar's Chess tactics for champions.
Wrong Polgar Susan is the author if you have her book you don't need another to explain tactics fundamentals she knows what's she's doing your in good hands.
To improve your vision solve problems a hell of alot of them mates 1 2 3 4 5 6 7 combinations in bunches again and again through your minds eye without moving any pieces on a chess set or on a computer even solving 35-40 minutes a day helps. Some people immediate improvement in their game after solving for only a couple of weeks others see a big improvement after 6-9 months of consistent effort everyone is different.
1001 Winning Chess Sacrifices Combinations by Fred Reinfeld
http://www.amazon.com/1001-Winning-Chess-Sacrifices-Combinations/dp/0879801115/?ie=UTF8&qid=1387762788&sr=8-2&keywords=1000+chess+combinations
1000 Brilliant Ways to Checkmate by Reinfeld:
http://www.amazon.com/Brilliant-Checkmate-Chess-lovers-library/dp/0879801107/?ie=UTF8&qid=1387762867&sr=8-1&keywords=1001+checkmate
Play through game collections full of minatures like this one again and again backwards and forwards time yourself with a chess clock:
http://www.amazon.com/1000-Best-Short-Games-Chess/dp/4871875741/?ie=UTF8&qid=1387761884&sr=8-1&keywords=1000+best+short+games+of+chess

I've gotten a lot of use out of Combination Challenge! by Lou Hayes and John Hall.
Hi, I would greatly appreciate it if some knowledgeable players can write in and tell me what would be the best tactics book for me to increase my rating. I already own Seirawan's winning chess tactics and Judit Polgar's Chess tactics for champions. Currently I'm looking at Richard Palliser's The complete chess workout or Reinfield's 1001 winning sacrifices and combos. Any suggestions would be greatly appreciated.