Ive tried Capella Chocolate, and it's really good with FlavourArt peppermint.
Ive made a firm decision to stick with FlavorArt peppermint, but curious on other chocolate concentrates.
Here's a helpful guide for choosing your peppermints btw: http://i.imgur.com/QM9b5CU.png
HS Australian Chocolate if you're going for the darker sort.
When I make mint chip I usually use CAP Chocolate Fudge Brownie and TPA Creme De Menthe. Chocolate Fudge Brownie is crazy strong though. I usually use it at 0.05%-0.1% TPA Creme De Menth I use around 1% - 2% depending. If you want a cool mintyness maybe add a touch of Koolada or TPA Mint Candy or FA Peppermint.
If you can find it, CAP used to make a Mint Choc that is delish. Otherwise, I like FW Dark Chocolate
The chocolate question has been burning me up for awhile. I see so many different comments, i just want a good place to start. Heard good things about FLV mill chocolate but bullcity was out when i was putting my order in and couldn't remember some of the other good ones.