There are three kinds of dynamic views: photo-oriented templates (flipcard, mosaic, snapshot), text-oriented templates (classic, sidebar) and magazine-like templates (magazine, timeslide). If you don't have a photoblog, classic, sidebar and magazine are the best dynamic views for your blog. Blogger's new templates bring a lot cool features and change the way readers interact with a blog. Infinite scrolling replaces pagination, blog posts are loaded using AJAX, Blogger caches blog posts so they load faster, images are downloaded as you browse, you can use keyboard shortcuts (j/k or n/p) to go to the next or previous post just like in Google Reader. There's also instant search that shows the list of results as you type.
While dynamic views have many cool features, there are also many downsides. They're not very customizable: you can only upload a header image and customize the background colors. When you pick one of the views, all the gadgets you've added will disappear. It's also annoying that blog posts no longer open in separate pages: they open either in lightbox-like panes or in a homepage-like interface, next to other posts (here's an example). Just like the mobile template, dynamic views only work with Blogger's commenting system, so you won't be able to use Disqus. It will be interesting to see how search engines handle the new templates, considering that blog posts are loaded using JavaScript and HTML pages are almost empty.
I don't intend to switch to one of the dynamic views, but my favorite templates are sidebar and magazine. You can always bookmark these links or use Google's Chrome extension, which needs to be updated to add support for the two new dynamic views. Some Google blogs have already switched to the new templates: Blogger Buzz, Gmail Blog, Google Docs Blog and LatLong.