I'm another mineral makeup convert (probably about 2 years ago now?).
I have used: Cory cosmetics, J. Lynne, Bare Minerals, and Everyday Minerals and like them all. The WAHM/smaller companies give you more bang for the buck. Right now I'm into Everyday Minerals and really like their products (and they have free samples).
Cory gives a little more coverage, and colors tend to run light. A lot of really fair skinned people like that company if they can't find matches in other lines. I'm not fair (more of a light olive) and I was able to find a decent match. Samples are inexpensive there too. Cory has great eyeshadows!
J. Lynne is great as well.
Bare Minerals...I like, but is expensive for the amount of product in comparison to the other brands. I like an eyeshadow I have from them, but it will take FOREVER to use. I mostly use sample sizes for eyeshadows (from all of the above companies) because one full-sized bare minerals eyeshadow would IMO take an eternity to use. Bare Minerals sells mineral veil to go over their foundations, and that product *does* contain parabens, so I never used it.
Some have more sheen to them (like Bare Minerals). Some come in varying finishes (Iike Everyday Minerals...I like the semi matte). Cory is very matte. The different brands do vary in their ingredients somewhat. Some people find they are sensitive to bismuth or mica. If that happens to you, rather than giving up on mineral makeup, consider trying a different brand without mica or without bismuth.
I like that mineral makeup doesn't have parabens and phthalates. It doesn't really go "bad" or separate. It has sun protection built in. I find the colors are bit more forgiving than liquid foundation, and you can "tweak" your color with the season (adding a little darker foundation to your summer makeup for example, or making your foundation a bit more yellow or pink). It doesn't feel like you are wearing makeup. There is a learning curve to the application (always start w/ just a tiny bit and go from there...most people really overdo it initially). I do a "damp" application which is different than what you see on most infomercials or what most other people do. I read about it online and it works the best for my skin.
It does kind of a mess of my countertops but I'll live with that
