Of course, GWT is not perfect. DevMode needs to be faster, and they need to integrate scala-gwt. :-)
I wrote a Backbone-like framework to deal with some of the boilerplate (http://www.tessell.org), especially if you're doing MVP. I don't quite have a solid DTO story down yet, but overall I like it.
If I had to use a server-side framework again, I really liked Click (http://click.apache.org), as it is component based, but has source code you can actually read (vs. both Tapestry and Wicket which are too big/magical IMHO).
Google App Engine cause we hate doing sysadmin work. Objectify. Cambridge Template Engine with JEXL. RestEasy/HtmlEasy. Jackson. Guice to bind it all together. Front end is heavily CoffeeScript, Handlebars, Jquery, LabJS, customized bootstrap and various other libraries. We've got a credits page full of links to the above projects... https://www.voo.st/about#credits
Overall, I'm pretty happy with this choice. We've had to do some weird and semi-complicated stuff to integrate it all together, but at this point, it works quite well.
I've never really understood why Stripes hasn't "caught on." It's simplicity is wonderful.
Most of the history of Java web frameworks focused on ways to make form processing easier. Nobody (sane) does html form processing anymore. The "framework" needs to be little more than a way to render html templates and an rpc mechanism.
For MVC type (like ASP.NET MVC not Rails): SpringMVC
For ASP.NET type: JSF 2.0 (I heard they simplify it greatly)
Used Play for a few projects, but don't like that 2.0 is more or less getting rewritten... don't like Spring... not sure what is left (JEE6 and JSF2? God I don't want to use JSF again unless it changed significantly)
Somehow I managed to use Wicket for well over a year before realizing the benefit to this approach.
Host on Glassfish v2.