If you don't want to wait, Reinforcement Pack and Broken Alliance are the only two DLC I'd say are mandatory right now. The rest add additional campaigns that take place after the first (and some can upload your fleet from an earlier campaign) so you can buy those at your leisure. But Reinforcement Pack adds some indispensable ships to the roster and Broken Alliance fleshes out the story missions in the first campaign.
Hope this helps!
Thanks for the post. Really interesting for prospective new players.
One thing that the publisher is not doing well: making clear what improvements in the DLC apply to the original campaign and which do not. Especially the new units: are they for the sequel campaigns or they appear in every one?
"New war room
The Ministry of Defense relies on Galactica to lead the counter-offensive against the Cylons. Organize and command BSG-75 from a meticulous reconstruction of the famous Galactica CIC. The Season Two strategy layer has been revamped to get you straight into the fights that matter, while the new Cylon Threat mechanic measures your overall impact on the First Cylon War."
Does this means that, upons installing this DLC, interface improvements will appear in the original campaign?
This kind of questions are posed because of the DLC/sequel delivery model that Civilization IV-VI and Paradox and others are using: Before, we had complete games, then there were add-ons, sequels, minor improvements (or, sometimes, mayor improvements when the game was more mature).
Now we see that are launched half-finished, crippled by design, with the promise of future expansions/DLC to fill in the holes.
So this is what I am really asking about: Is the original game a complete one and the DLC optional, or does it feel shallow or incomplete and some DLC are strongly required?