Though they aren't all great, I have a soft spot for Axl visual novels. I mainly read VNs for comedy, and they have some pretty unique ones.
A personal favorite of mine is a VN by alcot: Onigokko, which was a riot all throughout.
Some other companies I like: some yuzu-soft, certain circus (ahem da capo), some Will (including games under their engine like pulltop and ensemble), some August, akatsuki works, early Lump of Sugar, akabeisoft2, some of Saga Planets, and some others I can't name off the top of my head. I honestly care little for the over-all writing, as long as they entertain me. Games that're serious all throughout I give a pass.
I used to go on an all-out binge of VNs every quarter, spending hundreds of dollars, but after plenty of spectacular disappointments I stopped by 2010, after some pretty lackluster games. Now I trust to word-of-mouth and personal research before buying.