Yup, natty PB is a great one, or almod butter. Almonds are one of the best fat sources you can get. Still another is olive oil. When I first read of using EVOO in shakes I thought it was suspect, but it worked out really well as you don't need to add much to get a ton of good calories in. There have been studies that show that many of the "healthiest" areas in Europe generally have higher EVOO intake.
Current PRs at 242, raw w/ wraps- 525, 355, 605, 1485
Roboro tui, perimo vester adversarius
(Build yourself, destroy your enemy)