About to have our lab operational. After looking at the Wiki, I see there are several items on the list that look interesting. My question is this: Which CT Lab products are actually worth building and which are not?

All of them, really.

They're all worth it to a certain extent, but first you have to discover them which can use up alot of research.

and you discover them randomly.... good luck getting the good ones first

Almost everything is pretty nice, honestly. The resource structures add nice bonuses, especially after you have a few of them. The Veloxes and Aegis are great, even though it takes forever to hoard all the stuff for them. The governance probes are pretty weak, and the Gravimetric Flumes require ridiculous numbers of artifacts for some fairly crappy scanners.

definitely, between all our members, we haven't had a new discovery in over 2 months and between us we've delved over 600K RP into finding a new tech in the CT lab. The odds are really against you with this, just be prepared to use up a LOT of RP