If you're willing to pony up $8/month StockFetcher is really good. I use it myself for finding opportunities using linear regression slope and channels, something you won't find in free scanners. It's a really good value.
Barcharts.com is pretty good and actually prefer it over my built in screener (tos platform). Barcharts has free features and if you sign up, you can build your own. I personally trade morning gaps and get 80% of my trades from here.. http://www.barchart.com/stocks/gapup.php http://www.barchart.com/stocks/gapdown.php