Basic Fantasy Role-Playing Game
Ease of Use- BFRPG is one of the simplest yet functional RPGs I've seen in a long time. The easy mechanics and basic options are quite easy to use, yet they give a very firm base to the game. There are only 4 classes - Fighter, Cleric, Magic User, and Thief - and yet you can create almost any archetype imaginable. The rules for combat are short and orderly as well, yet they cover almost any possible situation. A quick section on optional rules allows the GM to make his or her preferred changes to the game through a "canon" base, and gives newer GMs an opportunity to experiment with changing the rules. These flexible yet solid rules provide an excellent base to work from.
Modern Ideas- While taking cues from the original (before Advanced) version of D&D, BFRPG is based in part on the 3.5 SRD. Some grognards will laugh at me for saying this, but there are actually a lot of new, good ideas out there. BFRPG takes the best of these (such as ascending armor class) and incorporates them into its system flawlessly. These new ideas make the game attractive to players of third and fourth edition who are looking for something different, as well as making it distinct from games that directly clone OD&D.
Community- BFRPG was based on Chris Gonnerman's ideas, but was shaped immeasurably by the Dragonsfoot community. The rules have thus gone through countless revisions, so many that I can not find an error in the core rules yet! Also, the community is devoted to churning out countless modules and supplements (see next reason).
Resources- There are, I believe, 21 free, fan-created rules supplements (counting the articles in the Old Dungeoneer's Almanack) on the BFRPG downloads page. There are also 11 modules (three of which include several separate adventures and one which includes a sketch of a campaign world and a "home base"). Finally, there are 9 character sheets (one of which comes in 5 different languages) and four DM sheets (including a spreadsheet of all the monsters available so far). BFRPG is also compatible with great, old school modules like Keep on the Borderlands (of which a homage version is also available on the site).
Art- The art in the BFRPG core book is as good as any I have seen so far (in a RPG book, at least). The giants (by Luigi Castellani) and the Stirge and Shrieker (by Andy "ATOM" Tailor) are especially great.
Well, those are my high points of BFRPG! What do you think?