I think I'll defend my selection a bit, here:
1. Colt Walker - the Walker is interesting/unique because it's the most powerful handgun until the invention of magnum cartridges. As well, it's used by Clint Eastwood's character Josey Wales in the similarly titled movie. The other neat thing about it is its grand size, you ever seen one of these?
2. LaMat - interesting not only because it's a revolver with a shotgun barrel in the middle, but because it's an example of how "superior design" doesn't always win out. The LaMat feature ten shots before reloading, yet Colt and Remingtons designs holding 6 proved more popular and outlasted the LaMat.
3. Colt 1903 - simply because it looks cool and Bonnie Parker used one to break Clyde Barrow out of jail. Neat bit of history behind it.
4. S&W Model 29 - this gun proves how much power popular movies have over the gun industry. As the Model 29 wasn't a largely popular gun until Dirty Harry and Taxi Driver were released. It's a seminal gun in gun history, but it took Hollywood to make it popular.
5. Colt 1851 Richards Mason Convertion - I kind of just like these. I would feature the original 1851, but the RM conversion is much more interesting to me. It signifies the tenacity of the old Colt c&b revolvers, proving that they are not obsolete and just need a simple modification to remain up to date.
6. S&W Model 39 - S&W's first semi-automatic model. It features many things only previously found on European handguns and was used with a silencer as the "Hush Puppy."
7. Nagant Revolver - The only easily silenced revolver. Plus, it's history during the Russian revolution.
8. Walther P-38 - The standard handgun of the Nazi regime. Many of its features and design aspect would find their way into many handguns that we now use and take for granted without thinking about where they come from.
9. Walther PPk - Walther designed this not to be the Nazi Police/SS side arm, but rather as a simple small, concealable police carry weapon, but the gun found itself in the hands of Nazi officers, SS and Police. The gun then went on to be used by James Bond in Ian Fleming's novels and the Eon movies. This is an interesting dichotomy for this weapon, as it's most prominently featured in our minds in the hands of Nazis and James Bond. Plus, it's believed that Adolf Hitler committed suicide with a Walther PP. That's enough to get a PPk into my "interesting" collection.
10. Nambu - again, another inferior service handgun from the turn of the century. It's an interesting and minimalist design that inspired Ruger to create the Mk1 .22