Unfortunately, I’ve only read the first 83 issues and every issue since 2016, so I can’t really choose from a large list of favorites. However, out of those writers my opinions are so:
Ennis is the best. I enjoyed every storyline, but as with pretty much every fan of Constantine, Dangerous Habbits was my favorite.
Delano had his ups and downs. I really, really liked Original Sins and Newcastle, but I really, really disliked the Fear Machine and one other story arc who’s name escaped me. Overall though, I believe it was good.
Simon Oliver was decent. I didn’t read the New 52 run of Constantine, but I heard it changed a lot like kicking him out of England and having him interact more with other DC characters. I thought Oliver was able to strike a nice balance and bringing back characters like Mercury was nice.
Tim Seeley is somewhat forgettable. Honestly, I almost hit reply on this post without including him because I completely forgot about his run. It wasn’t bad, it just couldn’t hold my attention and I was usually looking forward to reading other books when I would stop by my local comic shop.
Finally, Spurrier I feel it’s too early for me to give a final decision on, but I think it’s good so far, issues 4 and 5 especially.