Team Fortress 2

Valve has continulously updated Team Fortress 2 atleast once every few months since it's launch.  Usually every update adds new weapons for one of the 9 classes and new achievements for that class, a few maps, and maybe a new mode. The thing that's different about this update is that it doesn't offer and new weapons or achievement for any class, hence the name "classless update".   
         
Instead Valve has added a new game mode with three maps for that mode, 1 being new and 2 being olds maps converted for the mode, a new arena map, 18 brand new hats, the Sawmill map converted for Capture the Flag, and other various gameplay tweaks.      
 

Gallery

The good news is that the new mode is awesome, and the brand new map to go with it is just as great. I'm speaking of King of the Hill_Viaduct. The new mode has one control point in the middle, similar to arena. But you have to capture this point and hold it for a total of 3 minutes. If you lose the point your time doesn't reset, it'll remain at the time it was when you lost the point. The Viaduct map is the first official Valve map that has been featured in snow, but other than that, it's just a very small map with a capture point in the middle.   
 
The other two new existing KotH maps are Nucleus and Sawmill. Now, I never liked arena Nucleus, so it makes sense that I'm not a fan of KotH_Nucleus, but KotH_Sawmill is probably my favorite KotH map, but Viaduct is great too. 
 
Another thing I'm not a fan of is the new arena map, Offblast. It's similar to Nucleus in design, just basically a giant rotating mountain. It does offer something no other map has in that you do have the oppurtunity to blast people off of the mountain, causing them to fall to their death (the Force-a-Nature and regular flamethrower=win). What's kinda cool along with that is the creator of the map has been made into the 10th class.* 
 
And really that's about it, aside from all of the hats that have been introduced which are extremely hard to obtain (you'll just radomly receive them, like you do weapons) so that's unfortunate, but then again if they were common they wouldn't be as cool to have. There are also gameplay changes, such as the scout's Sandman no reducing 30 HP instead of taking away double jump, but it's not worth going into all of those. Oh yeah, try not to loose, because if you do you'll probably laugh yourself to death.
 
Final Decision 
You can't really complain about these updates, they're free, consistent, and always get you back into Team Fortress 2. At this point there's just so many different maps and game modes in Team Fortress 2, I don't see how you couldn't like the game. Everyone is going to be able to find their favorite maps and game modes, and if you can't do that, then clearly there's something wrong with you. 
 
*I am lying.