I'm interested in watching the following comedies, but I don't have the time to watch both the theatrical and the unrated versions.

The 40-Year-Old Virgin
Anchorman: The Legend Of Ron Burgundy
Anchorman 2: The Legend Continues
Bridesmaids
The Five-Year Engagement
Forgetting Sarah Marshall
Funny People
Get Him To The Greek
Knocked Up
The Other Guys
Pineapple Express
Step Brothers
Superbad
Talladega Nights: The Ballad Of Ricky Bobby
This Is 40

For those that have sampled both versions of any of these films, which do you prefer? Feel free to recommend other comedies that aren't on this list.

hmm as far as I know the unrated versions have a bit more "adult" humor. Mostly that involves tits and sex jokes and more bad language. Some people like that, others feel it's more childish. it's a personal preference really. The unrated versions don't really make the movies better or worse so you might as well go for those unless you don't like crude humor.

I generally feel that a lot of so-called "unrated" or "extended" cuts of movies are really not worth it, whether it's a comedy or anything else. They tend to add either only a few seconds of completely inconsequential stuff or so much inconsequential stuff that it destroys the films pacing. Most of the time, it really just seems like a marketing trick.

Unfortunately, I haven't seen any of the films on your list except for two, but I'd recommend this site, which has detailed comparisons of the various versions of films. Often, they also put a bit of evaluation in a report's introduction about which version is the better one. Here's an example of that from their Get Him to the Greek article: "The extensions are rather lengthy pieces and not very subtle, however it is questionable whether one really needs the additional scenes because they seem to slow the movie down quite a bit. "

Of your list the only one that I found to have really funny moments is the Pineapple Express the rest are mostly lame attempts with clichéd jokes.

If I have to recommend comedies I would say anything by the Zucker brothers (Airplane, Hotshots, etc.), the Pink Panther movies with Sellers including A Shot in the Dark, Broken Lizard's Super Troopers is very good, their other movies are mostly lame but occasionally have funny situations, and Shaun of the Dead and Hot Fuzz.
And let's not forget the Monty Python movies (Holy Grail, Life of Brian, etc.) with their absurd humor.
Then there are a lot of 80's movies like Ghostbusters, Stripes, 48 Hours, Beverly Hills Cop, Gremlins, even the original Star Wars trilogy had a lot of funny moments (Han Solo vs. Leia) which the new trilogy replaced with toe cringing. :^/

In the context of these so-called "comedies" the term "unrated" is just a shorter expression for "the same lame, unfunny movie but with 20 seconds of gratuitous naked tits".

For either version you're better off browsing the intertubes for 90 minutes...

Superbad - This is one of my favorite comedies and I've looked into the differences between the two, go for the Unrated on this one, it contains a lot of extended dialogue bits that make the movie more comical without dragging it down.