I don't know about "go to" but it's one of the biggest. This article is pretty decent as an overview of DAFs -
https://www.morningstar.com/articles/1039795/pros-and-cons-of-donor-advised-funds
Based on your limited first post, here are a few things to think about. First, unless you are seeking to front-load the donations for tax purposes, it may not be best to use a DAF. Second, your ability to designate where the funds go in the future is limited to public 501(c)(3) charities. Finally, your designation of public charities is merely a request - you don't have the *right* to force the DAF to send money where you direct. If, for example, Fidelity (or any DAF) has (now or in the future) a restriction on supporting hunting causes, you may not be able to convince them to use the funds as you intend.