I really learn a lot by listening to Jeremy Crawford's Sage Advice segments on the D&D Podcast, Dragon Talk. Unfortunately, he's not on every episode, and it can be time consuming trying to find the Sage Advice episodes on their website.
I finally broke down and compiled all episodes with Sage Advice segments for myself, so I thought I'd share the list with you. I'll try to keep this up-to-date. Please let me know if I've missed any.
You can listen to the episodes on the site, or you can download them directly using the download link. I give the release date of the relevant episodes. I also give the starting point of the actual Sage Advice segment. This list gives the Sage Advice topic as opposed to the podcast episode title/topic.
Sage Advice Segments
This list was last updated September 7, 2019.
11/17/16 - Armor Class Calculations (6:51) download
12/01/16 - The Lucky Feat (2:58) download
01/19/17 - Spell Targeting (5:18) download
02/02/17 - Temporary Hit Points (4:10) download
02/09/17 - Reactions (4:45) download
04/05/17 - Druid Wild Shape (5:40) download
04/27/17 - Stealth & Invisibility (8:58) download
05/04/17 - Multiclassing (9:35) download
06/29/17 - Rules & Rulings (9:52) download
07/06/17 - Magic Items (10:41) download
08/03/17 - Grappling (7:45) download
09/21/17 - DM Etiquette (6:12) video
10/26/17 - Polymorph (19:35) download
10/31/17 - Anti-Magic (11:00) download
11/16/17 - Conditions (10:07) download
12/14/17 - Illusions (12:37) download
12/20/17 - Playtesting (6:18) download
01/25/18 - Building Encounters (9:05) download
07/25/18 - Traveling to Other Worlds & Planes (15:40) download
08/02/18 - Sage Advice (11:19) download
01/17/19 - Sage Advice (14:53) download
01/31/19 - Bonus Action Timing (14:51) download
04/18/19 - Customizing Monsters (15:34) download