looking for top of the line equity and options execution and rates, and platform. Which of these 3 should I go with? Lightspeed, OH, or Sterling
Lightspeed is certainly a better platform than Sterling. But Sterling has cheaper rates. If you are a scalper or high frequency trader, you are better off with Lightspeed. If you are a position trader, Sterling will work. Don't know anything about Optionshouse. I personally used to trade on Lightspeed.
I use OH but have never used Lightspeed or Sterling so I can't directly answer your question .... Feel free to ask any specific question about OH and maybe I can be of help.