This list was taken from the forum here, but just shows how and why there's so much love for the game, and people keep coming back to it:

  1. No book keeping. You move, recoil, fight, flank, die. No crappy chits ruining a perfectly good wargame table. No casualties, slowly weakening units, rallying phases, or defensive fire... 
  2. Army lists all in one book. TTS has easy to download army lists, but still. Really nice that it's all there
  3. Wargame table that looks like a battle map from the books that I've read. Blocks of troops supporting each other, instead of just running around like we're playing Warhammer Fantasy Battle...
  4. Easy to modify. Easy to figure out new troops, modifications. etc.
  5. Easy to scale. DBA = 12 elements, and BBDBA = 36 elements. Love it!
  6. Cheap - no need to spend a fortune on a pile of figure, many of which never get painted!
  7. Quick to Play - I’m old enough to remember WRG 7th edition, where we rarely finished a game.
  8. Relatively Realistic - I say ‘relatively’, because no wargames rules are completely realistic. 
  9. Encourages historical study - Building matched pairs is affordable, encouraging historical battles and scenarios
  10. Time efficient - Small armies allow for that extra time to add a little bit to the painting, bases and terrain building
  11. Campaign friendly - Campaigns done and dusted in a weekend
  12. Allows for breadth of interests - "Butterflies" like me can skip around the historical timelines with ease, particularly with the later adaptations.
  13. Teachable - Basic competence with the rules can be taught in an afternoon (my six year old beat me in his second game...) and last but not least...
  14. Fanaticus - this is a fun forum!
  15. When you build a 15mm BBDBA army, you can use it for many many other ancient/medieval rules sets, because DBx basing is used in like EVERY ancients ruleset out there. DBA was the OG.
  16. The small armies make it relatively easy to paint suitable opponents, or even to paint an army specifically for a themed competition.
  17. The armies are easy to store and move about. Even at 28mm scale.
  18. Newcomers can learn the rules quickly
  19. The rules system is forgiving of mistakes. If an error is made in rule interpretation it rarely if ever ruins a game. I put it down to fog of war!
  20. Easy to shrug off disappointing/boring games. Just set up another and move on! How many times with other rules did we play a clunker of a game that took all night/afternoon to play.