Ask a simple question and get a book. 
Honestly, I don’t have a “the best”. 1) because I haven’t tried all of them. 2) because I haven’t tried everyone’s specialty. 3) because I have favorite dishes at different spots, instead of a hands down favorite Ethiopian spot. First, I want to try a few new (to me) places and revisit a few oldies - your favorite, Buna (looks great!), one of your not so favorites, Meals by Genet (loved by many), revisit Messob and definitely try the Chicken Tibs at Awash. But honestly - and I’m not a vegetarian, definitely not vegan - my favorite vegetarian combo platter could be Rahel. Because they’re vegan and competing with non-vedge places I think they put extra care with seasoning and preparation in their dishes which are excellent. I had given up on Awash for a while, because I couldn’t find it, lol. Not that I was trying too hard, but for a while I would detour on my way home from work and look for it based on my co-workers landmarks (they didn’t remember the name or exact address, because “we just know how to get there”.) Another deterrent was people saying they were ignored or received rude service. It dawned on me that Awash is not on Fairfax, has a nondescript storefront and ignore their non-Ethiopian diners, because they’re more interested in catering to regulars and the Ethiopian community. But I’m over that now, lol. I just haven’t been, but I must try the Chicken Tibs that everyone raves about.
This is a really good thread and it’s inspiring me to try the places I’ve been putting off and new ones I hadn’t heard of.
If you don’t mind, I’ll share a couple of my reviews:
Desitenya Mebilati!