I started getting into fashion magazines in 2007-8, and although I of course know about legendary editors of the past, have browsed vintage issues on this forum and watched documentaries, I'm only going to mention Editors who's magazines I got to experience and immerse myself in.
For me, number one would be Carine. Her French Vogue is instantly what I think of whenever I hear the word Vogue. The glamour, the sexiness...it was so chic and everything a fashion magazine should be. It truly was the perfect storm of the right editor at the right time, working with the best mix of established and upcoming photographers and models. It was provocative, it was beautifully designed with stunning layouts and covers (a rarity these days), it was genuinely exciting to see what was coming next - every month was an event. Truly electrifying.
Next has to be Anna. Although I think she is incomparable amongst the modern editors, I had to give her the second spot because the final results were sometimes (maybe even often) lacking. However, her ambition, her power, her business savvy, her absolute understanding to the core the brand and audience she was working with and for is unrivalled. It's not the same as it once was, but it's also not the right era for the best of Anna to shine. Late 90s to mid 10s (and in particular the early-mid 00s) was, again, the perfect storm of the right editor at the right magazine at the right time, and it's the era I'm really talking about here when referring to Anna's Vogue. What I admire about her vision of the magazine is that even if it was not always to our tastes as fashion fanatics, she absolutely committed to what the American version needed to be. Her influence on fashion, publishing and pop culture is astounding and I still go through US Vogue threads on this forum from years ago and love reading the reactions, the criticism, the frustrations, the celebrations.
Honourable mention goes to Franca. Although I often found the design and layout to be quite poor, and didn't have much interest in the general direction of the rest of the magazine; the covers and shoots she produced with Steven Meisel over the decades are truly legendary. The work she commissioned from him his amongst the most sublime fashion photography ever created and resulted in some of the most beautiful Vogue covers we've ever seen.
Lastly I want to throw Alexandra Shulman's name into the ring. Was her Vogue the best version of the magazine we've ever seen? No. However, she was a great editor in that she absolutely knew who the audience was and crafted a well rounded magazine to appeal to them. I think she balanced the commercial and the creative even better than Anna, but then she also had more flexibility to do so. Many dud issues and underwhelming covers, but also a lot of truly fantastic ones as well - when she nailed it, she really nailed it. Her Vogue could be beige at times but overall it had a clear identity and it appealed perfectly to its core audience (as limited as that audience was). By no means am I saying her Vogue was a perfect magazine, and she herself had many well-documented faults, but as the Editor of that specific version of British Vogue she did a fantastic job and I cherish a lot of her issues.
Overall I think the era when these 4 were in charge at the same time was fantastic. Each edition had its own identity; it didn't matter that US Vogue had celebrity after celebrity on the cover because Vogue Paris would come along with Natasha Poly or Lara Stone fronting the magazine. Each one played a different role and I always liked that I could indulge in a highly-commercialised version of the magazine and in the same month delight in a really creative, provocative vision for it as well. As a collective, there was a really nice balance amongst these editors and editions.