You can make awesome landing pages using the
Genesis Framework including video sales pages, video landing pages, launch pages and a whole lot more. It's not the cheapest option but it's one of the most flexible and you can use it on as many sites as you like.
For sales, landing and squeeze pages I like
FlexSqueeze which comes with an unlimited site license.
You could also use OptimizePress however the caveat being that people are moving away from it and heading over to Genesis which can do much much more.