What is the best chocolate in chip form to use in baking?

If you can get Tcho chips they are excellent. I believe you can get them thru mail order. We use them in many of our cookies!

Guittard chips are very good quality, and I often use them. However, I really prefer to make uneven slivers and chunks off a large block of chocolate.

I like chopping up a block of chocolate into slivers or chunks and using that instead of chips. You can get a higher quality chocolate than is usually available as chips, and I think is often cheaper. I usually use the Callebaut 60 or 70% bittersweet.
If you want the chip shape, I also like the Guittard "extra dark" 63% chips that Stephanie recommended.

I'm with cookbookchick -- love the ghirardelli 60%

I like Guittard-the super chips in the yellow package.

I like Guittard 63%...in the red package.

http://sweets.seriouseats.com/2010/06/what-are-the-best-chocolate-chips-brands-for-baking-cookies.html

My personal favorite is Ghirardelli.