xterm
As the title says, what is your window manager or desktop environment of choice? To make things easier to follow lets break things down into questions and maintain the layout properly.
1- Name
2- Pros from your perspective.
3- Cons from your perspective.
4- If you were the lead developer, what would you change or add?
P.S.: Post that follows is my personal opinion. Use the same layout please.
xterm
1- Name
Blackbox/Flux
2- Pros from your perspective
It's simply light, that's what i enjoy it the most. It's incredibly fast and cleans up your desktop nicely. One of the main reasons why i enjoy linux is that you can keep things as light as possible, a treasure you cannot simply get in other operating systems. Combine that with Fluxbox or Blackbox, you'll enjoy a smooth UI experience.
3- Cons from your perspective
Defaults. The defaults do not contain enough shortcuts for my taste, you'll have to download a separate extension and configure everything yourself. It would be nice to have some default key bindings that map to common scenarios. Additionally, a sort of smart lookup system that adds your applications accordingly to the menus given that those are not configured for you (fully).
4- If you were the lead developer, what would you change or add?
I'd probably create separate builds that target specific distributions and populate the stuff i said in point #3 by default based on how the system is preconfigured.
Joe
1- Name
Xfce
2- Pros from your perspective
It's a good compromise between the speed of window managers and heavyweight desktop environments like GNOME or KDE. It is however a full fledged desktop environment, that comes with its fare share of applications, and utilities.
3- Cons from your perspective
It's a compromise, so it's slower than other window managers and won't look as pretty as KDE.
4- If you were the lead developer, what would you change or add?
The choice of default applications isn't always the best (Abiword, I'm talking about you).
leblinux
1- Name
Enlightenment (DR17) WM
2- Pros from my perspective
Eyecandy , fast , customizable endless support.
3- Cons from your perspective
i) Still under major development
ii)) Modules could crash (If the EFL libraries are not updated regularly)
4- If you were the lead developer, what would you change or add?
Transform it to a stable Desktop Manager that includes regular updates and port it to all major Linux distributions just to kill KDE :)