Online Brokers...which ones are good?

So which online broker do you use and why?

I use TD Waterhouse
Link is to the american site, but I use the Aussie one (www.tdwaterhouse.com.au) and trade on the ASX (aussie stock exchange).
Easy to use and understand, along with a useful site are my reasons......very well priced too.
 

[Keefe]

I use datek online....I like the real time streaming quotes and 10 second transaction guarantee