This is a hard one because when a Pro has a good partner the choreography tends to look better anyway, just because they can make their celeb do more (unless the visual interpretation is all wrong which a pro can sometimes get wrong no matter how good the celeb dancer is, like erin with the dolls, that was just stupid, the creative element behind that was all wrong)?!
When Flavia had Matt Diangelo her choreography was second to none for me that series. But with Russell (who aint as good a dancer) Flavs choreography is (expectantly) not shining as much as say Kristina who now finally has a good partner to choreography well for. And while Kristina herself did quite well to choreography funny and memorable routines for herself and John, to me, I wouldn't align those clever routines that were tailored to his skills (or lack of) as good routines but just well thought out routines for the dancer in hand. Memorable or funny choreography (that is typical for such a lesser dancer as John) may equal entertainment value but good choreography for me in when you actually see quality Latin/Ballroom being danced in front of you and as close to the art form as you can get with a Pro/amateur coupling. So while clever and entertaining choreography for lesser dancers is creditable, I don't see it as good because the actual dance quality isn't there (if that makes sense).
With Pros like Artem and Aliona they're both very style orientated dancers and can create either beautiful or alternative (or both) types of routines etc but when they persist on leaving out content (in this and last series) I'm left thinking i.e. ... nice contemporary dance with a bit of latin or Ballroom thrown in but would be nice if you can meet the challenge of creating a Latin/Ballroom dance where the contemporary element doesn't override the Latin/Ballroom aspect of the dance. Otherwise they're consistently good at creating styles of dance that aren't actually what the show is meant to be about (which is what I watch the show for)! I love their (so called out of the box) creativity but I want to see more Strictly choreography than SYTYCD choreography. If they didn't water dances down as they have done I'd say those two were the best Latin/Ballroom choreographers on the show. But alas I can't say that because sometimes I don't think I've actually seen a Latin/ballroom dance before me. In general I think any Pro that gets good celeb has more chance of achieving good choreography through most of a series. I think most of the so called rated celebs from each series was given good routines (by their Pro) more often than bad ones, and pob for the more common likelihood that it's easier for a Pro to create something good when they already have a talent to extend their vision from. So I think it depends on the year if a Pro delivers good choreography more often than not. The last time I liked Brendan's routines was way back when he had Lisa Snowdon. Just a shame that lots of people didn't like her as some of those dances that year by Brendan were my definition of good (apart from that awful showdance... that was interpretation gone wrong again).