I can honestly say that I don't have a consistent build at all. Sometimes I go starships, but pretty rarely. The laser turrets are a very common unlock, I almost always have those. And actually, I tended to get transports, too, but now those are knowledge-free. Sometimes I'd do engineers mark II (but never III), but rarely on that now that they all have teleporting.
In multiplayer, during my first 10k of knowledge I tend to get both Mark II command stations and scouts II. Nobody else on my team gets scouts at all, so I tend to get the mark III fairly soon after. With starships I usually go raid or leech, but recently I did some riot, too.
Depending on the game, I might unlock spider turrets early, late, or not at all. And also depending on the game, I will either unlock counter-dark-matter turrets very early or not at all. Usually I get mark II force fields in the middle of the game, rarely mark III.
Hmm, but you were asking about early unlocks. I suppose I tend to unlock Mark II bombers more often than not, but it depends on what my special unit is. Often I'll unlock whatever that is, plus whatever from the base set makes the most sense paired with it. That's fighters or cruisers as often as it is bombers. If the early planets are lightly defended, then I don't have any need for bombers of a higher level for a while. And even if there is an ion cannon, I can just raid that with a transport full of bombers.
I used to do the fleet line of starships a lot, but more recently those really just take a lot of commitment to get to the end of that line. I usually prefer just the mark Is of a few other lines. If the AI has a lot of starships, then I'll do dread Is pretty early. I tend not to use the cloakers. For other turret unlocks, some of which I do soon in (but usually after the first 10k), I'll do probably mark II basic turrets and mark I missile turrets in addition to the laser Is I already have.
And from there... it really super varies. One of my favorite things about this game (if I do say so) is that I've never found an optimal build order, or even any must-always-only units (aside from transports, which is why they are now free of K). I tend to unlock absolutely nothing, except possibly laser turrets, until I've scouted as much as I can in the nearby area. Oh, and I almost never use the MRS, but usually my dad has one that is servicing our entire front line for the entire team, so that's just a case of specialization amongst players, same as they don't get scouts and one at most of us gets fortresses.
