Glad to see this thread on here. The Shining series is actually my favorite RPG series, and it's really a shame Sega never released a Shining Force sequel on the Dreamcast. Would've been great to see SF4 or a SF3 collection on their last console.
As for my favorite game in the series, I'd have to go with Shining Force 2. The graphics and soundtrack are top tier for a Genesis game, IMO. Also, the storyline's great and has a memorable cast of characters. My friends and I put a ton of time into the game back in the day, and would take turns playing the battles. Good times. Shining Force 3 is also great and has some iconic moments, but I still give SF2 the edge.
Shining the Holy Ark is also impressive, and I wasn't much of a fan of dungeon crawlers, but that game changed that for me. Highly recommend it as well. There are also some interesting graphical elements and animations seen in STHA that resemble effects in Golden Sun.
In regards to Camelot (formerly Sonic Software Planning), they are now an exclusive developer for Nintendo, working on their sports games. The last games they made were Mario Tennis Aces and Mario Golf Super Rush. It's a shame they aren't actively working on any RPGs, as I enjoyed the first two Golden Sun games as well.
I'm still hoping we'll see the series come back to life at some point, in a manner that respects the original Shining Force games. Fingers crossed.