I'm about to tackle mounting my TV in my brick fireplace surround and I have a couple of quick questions:

Is it ok to drill and mount into mortar joints only or is it better to drill directly into brick?

What are the best type of masonry anchors to use?

Thanks!

Drill directly into the brick with a hammer drill. Use a sleeve-type anchor with washer and nut to secure to the anchor.

Edit: if you don't have access to one, a cheap hammer drill at Harbor Freight will run you about $25-30 with a coupon and will be plenty sufficient. Just make sure you get the right bit size and don't drill too deep for setting your anchor

Drill into the brick, the mortar is too weak and will just crumble.

I have a pretty nice DeWalt hammer drill I can use. Why type of anchor is best?

You're looking for something like this:

After seeing someone crack a brick on 2 different occasions I have always gone into the mortar.

Hung a 70" tv on our back patio. Drilled into mortar to avoid cracking the brick. Everyone I asked said drill into mortar if possible.