The Braves consistently put themselves in a position to win the WS - whatever happens in the playoffs is due to other factors.  The Marlins on the other hand, put themselves in the position to miss the playoffs completely by trading everyone away.

I would rather make the playoffs every season knowing I had a shot at the WS.

If I had to look back at 17 years of a franchise in HBD, I'd rather have the Atlanta Braves.  I'd be significantly prouder of that team.  But if the question becomes "Which team was more successful?" I'm going to say the Marlins.  The point is to win the World Series, and while the Marlins may have been lucky to win the only times they've been in the playoffs, they still won more of them than the Braves have.

Ultimately the goal is to make the owners money and entertain us (in real life - in HBD it is to win and entertain us).  Whether they win the WS or not is incidental in my mind - it's the attempt at winning the WS year after year that keeps people coming back.  Look at the Cubs.  Are they a winning franchise?  No.  Are they successful in making a profit every year and providing a very entertaining atmosphere?  Yes, and possibly one of the best in baseball.  I think the only thing you can say the Marlins have over the Braves is one WS.  They don't have the fan base, they don't have any identifiable stars, they don't have history and they aren't making a profit.

The Braves achieved long-term success, including a championship and four WS losses, through shrewd trades, signings and player development, while the Marlins essentially bought one championship and lucked into another.

What the Braves did is more impressive in real life and in HBD.

I'm surprised more people haven't said "Marlins".  It seems like every debate I get into over "success" evolves to "I play to win the WS".    That said, I think success in HBD is meeting your team's goals.    I'd obviously love to win the WS every season.  But that's a retarded goal.    My primary goal is the playoffs.  Failing that, my secondary goal is contention until the very end.   After that, it's .500.  At my lowest points, it's avoid 100 losses.  Sometimes you have to adjust the goal.

In my mind, if you think failing to win the WS is an HBD failure, the game would be miserable.  Why pay $25 to be miserable for 3 months?

Braves.  No question.

I choose the Pittsburgh Pirates.

Didn't you get booted from Moneyball under the "Failing to compete" rules?     If so, yeah, Pittsburgh sounds about right for you.  Although Baltimore would have been an acceptable option also.

For an HBD team, I would rather be Atlanta, no question.
I think for "my" team in MLB, I would rather have the 2 World Series titles as an underdog than 1 and a bunch of playoff failures.  Really hard to relate since the Mariners are my actual team (as a Seattle sports fan, Two World Series Titles sounds really nice....)

After watching the Twins continue to flail about in the playoffs, I want my team to be like the Yankees.

doesn't everyone? that's the problem with baseball, one team has unlimited resources

The Yankees supply the Pirates with money to spend on players.  The Pirates do have resources, and choose not to use them.  If there's a problem with baseball, it's that not every team chooses to gives their best effort to win.