For the "current" standards of good looking and for skill levels attainable by people having a life (and/or job) it would be probably something like that (roughly in descending order):
* Basketball (for women tied with Volleyball)
* Decathlon (men)
* Sprint (men - women equivalent would be long and high jump)
* Boxing (all variants but only for lower to "normal" weight classes)
* Judo/Wrestling/BJJ/Gymnastics (lower to "normal" weight classes... maybe to sinew for women)
* Rowing/Kanu
* Olympic Weightlifting (lower to "normal" weight classes)
* Powerlifting (again lower to "normal" weight classes, additionally not at elite level)
* Swimming (men... women a probably higher in this chart)
If you allow "newcomers", I would add to above list CrossFit in the upper third for men (lower third for women) and Kettlebell (lower to "normal" weightlcasses) in the lower third.
Swimming would have been higher in the past, but for today's "standards" it allows a to "high" level of body fat compared to the other sports.
Football (aka. "Soccer") players only start to look "good" at a pretty high level (if they're not doing anything else), the same probably holds true for Baseball.
Additionally some positions in American Football (e.g. Receiver) and some Skiing variants would be ranked quite well.
Kanu? If you mean kayak, I disagree. Kayaking is good for upper body strength, but (exaggerating) atrophies the legs.
Also, I think there is a difference between 'good on average', and 'good for those who manage to do a lot of it without getting injured'. For example decathlon training is good for overall 'athlete look', but the risk of dropping out with some injury is fairly high.
For that reason, I would rank the impact-free sports such as swimming, cross-country skiing and rowing a bit higher.
* Basketball (for women tied with Volleyball)
* Decathlon (men)
* Sprint (men - women equivalent would be long and high jump)
* Boxing (all variants but only for lower to "normal" weight classes)
* Judo/Wrestling/BJJ/Gymnastics (lower to "normal" weight classes... maybe to sinew for women)
* Rowing/Kanu
* Olympic Weightlifting (lower to "normal" weight classes)
* Powerlifting (again lower to "normal" weight classes, additionally not at elite level)
* Swimming (men... women a probably higher in this chart)
If you allow "newcomers", I would add to above list CrossFit in the upper third for men (lower third for women) and Kettlebell (lower to "normal" weightlcasses) in the lower third.
Swimming would have been higher in the past, but for today's "standards" it allows a to "high" level of body fat compared to the other sports.
Football (aka. "Soccer") players only start to look "good" at a pretty high level (if they're not doing anything else), the same probably holds true for Baseball.
Additionally some positions in American Football (e.g. Receiver) and some Skiing variants would be ranked quite well.