Well, as long as you leave Scanlines (2x...) and Super 2xSaI the rest can go, and maybe keep Pixelate to still keep a GBA style lcd look. That's three useful and common pixel filters. I've explained my interest and reasons for keeping them and have given examples as to why they should be left:
Scanlines - - - Simulates playing VBA on a TV using the GC Gameboy player
Super 2xSaI - Looks quite nice and smooth for cartoon style gba games (Pitfall...)
Pixelate - - - Appears to give nearly the same result as a regular GBA screen
There are quite a few plugin renderers for use with Kega Fusion, and all in all most of them are the same. BUT, anyway, I'd like to have VBA-M keep these three. Scanlines would be my personal favorite to keep however if any others were to go.
PS: This is my first post, and just glad to join now since i just recently found out about a version of VBA finally seeing another new version after a long while. :-)