Episerver - which now includes Ektron as part of it's arsenal. Two things you need to know if you are considering Episerver - it has a crazy powerful search solution, Episerver Find, and a ridiculously robust e-commerce solution.
Those are the reasons we find our clients either have it, or are looking hard at it. With the addition of Ektron to the product line there is also a good amount of cross pollination going on - Epi has got a whole "user journey" and marketing package for personalization going on - all to drive users to that fantastic e-commerce module they have and convert them to customers.
They also take advantage of Episerver’s built-in self-optimizing multivariate testing, which will automatically make educated adjustments to the website based on which content blocks are generating the most traffic and the greatest number of clicks - again driving conversion and acquiring customers.
Anyway, we have been an Episerver partner for 5 years now and have certified developers available should you need help with your project.