Optimizely - A/B testing you'll actually use.
AB Tasty - AB Tasty is an all-inclusive platform for conversion rate optimization, personalization, customer activation, and testing.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Adobe Target - Adobe Target provides an intuitive user interface and an expanded personalization toolset.
Evolv - Evolv is the visual editor for web-based projects that are used to find better ways to connect with customers in order to improve marketing economics.
SiteGainer - SiteGainer is an A/B testing and conversion optimization platform.