As much as I happen to dislike the game, I choose UFO.
You can't go wrong with needle Reimu (and Wild Exorcism Dance is the best Reimu bomb ever), and the homing Reimu is actually good (the only other one I can think of is MoF's).
We had the last of piercing Lasers Marisa, and even if it was completely awful, the "All-range" Marisa was a neat idea.
Finally, even with Froggy nukes being better in every way than Snakes, both Sanae shots were really solid, and all in all Sanae was a nice addition to the playable characters, also it made me stop thinking of her as "Luigi-Reimu" :V