Can someone give me some feedback on the best forex brokers with tight pip spreads and at least 500:1 margin?

It sounds like you are a US resident too. US regulations prohibit Brokers from offering more that 1.50 on currency pairs. The only option I have found is to use one of few honest offshore Brokers. I have a link from the one I use to trade at 1.500.

 http://tradersway.com/?ib=1036365

Euro and Asian Brokers do not accept US clients. Hope this helps. Ted