Why Blender? First, it is well supported, and very stable. It is also ported to all major platforms. Blender is a full 3D suite. You can model, animate, make games, texture, and even use one of the best free video sequencers. The possibly coolest feature is that it is open source. You can change things as you like.

Blender has been long known as one of the hardest programs to get at all familiar with. Many people complain about how "bad" it is. The only problem with trusting these people is that most of them do not know how to use it. The key to learning is tutorials. There are some must see sites for any blenderer, no matter how experienced. I will list some of the most useful tutorial and general Blender sites below.

Official Blender Website: It has some good tutorials, as well as all the updates. It also has a very nice link page.
www.blender.org

Blender Wikibooks: Has some of the greatest blender tutorials, and definitely worth a look. This is where I started to learn blender :)
en.wikibooks.org/wiki/Blender_3D


Blender Artists: One of the most popular forums site, and has loads of good tutorials, and great support.
www.blenderartists.org

Blender Nation: Has loads of news for the regular blenderer, as well as some tutorials.
www.blendernation.com

Blender Tutorials Search: Pretty much a google search of many blender tutorial sites.
www.blender3dtutorials.com

There are many other sites which are worth a visit or two.

Here is the basic break down of the main features.

Mesh Modeling:
Features some of the most extensive features including advanced subdivision. There is also a cool sculpt mode.

NURBS Modeling:
Not the best tool to use for NURBS modeling, and only recommended for people who used to use NURBS modeling software. Supports basic features.

Materials:
Possibly the best UV mapping tools available. It is easily comparable to the best commercial products for UV. It also supports advanced materials using a great node editor. Support for Halos, and others. Also, there is support for light mapping, bump mapping, and all that stuff.

Animation:
Support for armatures as well as latices. You can either use envelopes around bones, or weight paint the model. The animation features were greatly improved after the 2 open movie projects.

Game Creation:
Has one of the easiest game engines to learn using "logic blocks". These blocks can speed up any game design significantly. You can also program up stuff for games in Python.

Scripting:
You can script up more features for blender in python. There are many add ons created this way.

Video Sequencing:
Has one of the most extensive free video sequencers available. There are many features to look upon, but this is the area I know the least of.

Exporting and Importing/Workflow:
Support for exporting and importing in most major 3D formats including .3DS, .OBJ, and .LWO. Many other formats are included, as well as many others can be scripted, or has been added as add ons.

Overall, Blender is the most advanced you can get. It is also my favorite program in terms of the number of features, usability, stability, and most importantly, the end result. You can get it at blender.org.