Edelweiss and Mountain Lily are good too (espacially Mountain Lily when she will get her bloomed form in one or more year).
But imho the two bests eventgirls currently available in permanent reissue are Hypericum and Geranium. Hypericum is a really good counter girl (and event counter girls is the best type of event girl, maybe better than some gacha counter girls). Geranium give you x1.2skill activation for the whole team based on affection. It's one of the best ability. Aside that, she as decent stats.
And Dipladenia could be a good choice too. She is not really good but she has +100 speed for the team and ignore panel that affects speed. It could be usefull in some stages (even if I think there will be no more stages with theses panel in the future).

And for information, next reissue give really good event equipment and next next reissue is Mirabilis, another really good counter event girl.