Sigil Staff - these seem to be the most popular right now, but I'm not looking to invest the 400k/$1,500 to get it to T5. And if I'm not going to do that, I don't see the point in bothering with it at all then.
Parasitic - I like the clench/raise mechanic of this flare to generate the weapon. But I don't know that I love the actual blood drain flare mechanic, plus the investment needed to get unlocked, although not as great as Sigil Staff cost.
Globus Elanthia - From what I've read, I do like the possibility of this flare. The investment to get it either already partly/mostly unlocked doesn't seem quite as high, it's already offering a script and regular flare as is. The fluff scripts, while definitely not the reason I'm considering it, are cool.
Greater Elemental - These also seem like a good option and the price isn't astronomical.
Fusion - While not flaring, this is definitely something to consider so that a wisdom or spirit regen orb could be added, but then you're missing out on the Cat B attack flare opportunity. But maybe that wouldn't matter so much because of the ability to add S6 Holy Fire flares and Ensorcel?
Animalistic - While a cool flare, this is something I'd be more likely to consider on my ranger and not my cleric
Sprite - I do also like this flare and it seems viable. Although a bit expensive to unlock, it's also not astronomical, but not something I'd unlock all at once though, for sure.
No script flare - or maybe I just say screw it and skip a script flare and stick to Cat B flares. These are easy enough to come by and I've already got a 4x/3x acuity and 4x void flaring in a locker from an older character.