I am thinking of further exploring my enjoyment of Linux by trying new desktop environments and desktop managers. However, I havent seemed to notice any differences other than aesthetics and maybe load time.

Are there any other things to consider when selecting a desktop environment or desktop manager other than aesthetics?

I guess it's just how it "feels" to you. I personally swear by GNOME; I like the simplicity, HIG, and the rapid growth in GNOME right now. KDE, however, has never felt right. I feel there's too much provided right at the start and too much messing with configuration to get it the way I want it. Whenever I try KDE, I end up trying to make it like my GNOME desktop so eventually I just go back. Same thing with the little I've tried of XFCE. But my opinion is worth little to anyone. Trust your own. Try each one and whichever "feels" the best then that is the one.

A good many DEs and WMs are alike. F'rinstance, many have the ol' 'start bar' idea. If you want something a little different, try something like FluxBox (or BlackBox, OpenBox... they're all basically the same, but different). I personally run SawFish - note, that is natively, not as part of Gnome. Some others you could think about are XFCE, WindowMaker, Enlightenment and ROX.

Happy playing

You really need to just use them to see which you prefer.
In the case of an up to date PC and a choice of Gnome or KDE it is entirely preference. You can load both on and use apps from either no matter which you are using.
I prefer KDE (konsole better than multi-term, terminal emulator in file manager, and lots of other little things). However Evolution and Pan kick ass over KDE Kmail and Knews, so I use those.
So on a modern high power PC there is no reason not to load both, use the one you prefer, and any apps you prefer.
Now, perhaps you just want faster or have an older PC. Take a look at ICE and Blackbox/Fluxbox. These use less resources so they are snappier on your newer PC or runable on your older PC.
The *box desktops are also very easy to customize as you wish while leaving your computer resources for the programs you wish to run.
As I said, you need to try them, why and what you want to be running on your PC helps make the choice.
Good Luck.

If I run a *box desktop, will that limit the applications I can run? I tried blackbox a while back ago and really liked it. I like how it is not structured like a windows system with the start menu, etc. however, I couldnt seem to run wine at all, but I could in KDE just fine on the same system.

By default, fluxbox does not have kde support compiled into it so you have to add it when you ./configure. After that, you can use all the apps that you would in KDE or GNOME without all the overhead that those desktops have.

You don't need Kde or Gnome support in *box to run these apps. You need the support when you want to use eg fluxbox as a windowmanager in Kde, or maybe it is for the Kde applets. You can run all normal applications in standard fluxbox like Konqueror, Wine etc. Just add it to the menu if you want it to start easy.

Would you be so kind as to expand on that?

Of course,
fluxbox's menu file is ~/.fluxbox/menu
open it with your editor of choice.

This line will add a new item in the menu with the name terminal that runs xterm.
[exec] (terminal) {xterm}

if you want to add a submenu do someting like this:

[submenu] (Browsers) {}
[exec] (mozilla) {mozilla}
[exec] (lynx) {rxvt -e lynx google.com}
[end]

[submenu] (name) {}
adds a new submenu
and [end] closes it.

You can have submenus inside submenus to.

I hope you understand, otherwise there are more documentation at fluxbox.org and there's also a nifty little gui app for fixing the menu at the above address.