For ASP.NET, indeed, WebForms can be a bit violent since it's essentially an abstraction that tries, with mixed sucess, to make you forget you're writing for the Web.
ASP.NET MVC, which came out 2 years ago, is much closer to RoR and other similar frameworks, and is a better abstraction in my opinion.
I don't think Microsoft is even still developing WebForms (last release is April 2010). Too many aspx sites are written in the old version of WebForms which turned the html output into a horrible and ugly mess. MVC3 is pretty much just as good as RoR or any other mvc framework about outputting clean html.
ASP.NET MVC, which came out 2 years ago, is much closer to RoR and other similar frameworks, and is a better abstraction in my opinion.