This is interesting question...I'm not sure how one would judge it subjectively!
But here's my totally biased list
Men:
1. Plushy - because IMO he is figure skating to me! Plus his longevity in the sport was incredible, right to the end his jumps were solid and while others can disagree I totally love his artistry! Whenever I watch a Plushy program I never get bored or distracted by something else.

2. Yuzu - He brings skating to a new level! An amazing competitor and I really love the different programs he's tried, from classical music, to Japanese music, to
Prince!
3. I wanna give a shout-out to
Jackson Haines who admittedly I've never seen skate, but I decided to look at who was behind modern figure skating and Wikipedia tells me this is the guy! Without him we wouldn't have skating as it is today, so much respect. Also check out the costume in the link there!
4. Stephane Lambiel - he might not have had the 3A, but his spins and the excellency thereof can't be denied! I'm really happy he's coaching the new generation of awesome spinners!
5. Dick Button - inventor of the Button Camel and the first to do a double axel! He pushed the sport forward and also has the honour of winning the European Championships...despite the notable fact he isn't actually European!
6. Kurt Browning - Owner of the first ratified Quad Toe in competition! Also superbly artistic, his
Singin' in The Rain ex is a sight to see.
7. Javier Fernadez - An inspiring skater! From failing to make the free skate in both Euros and Worlds in his first season skating (2006-2007) to being at the top less than a decade later, Javi's journey is worthy of a movie!
8. Yags - He's a four time World Champion and while I don't find his skating as watchable as Plushy's he was part of pushing the sport forward and it's interesting to see how he progressed artistically over his career.
9. Brian Joubert - He was the first man to land 100 quads in recognised ISU competitions, I also really liked his artistry too, he had some unique programs and costumes.
10.
Axel Paulsen creator of the beloved axel jump! He competing in speed skating as well and in fact performed the first axel wearing speed skates!
Ladies
1. Mao Asada - An amazing combination of technique and artistry with her 3As and totally boss step sequences!
2.
Madge Syers - A total boss, when she started competing there was no ladies division in the World Championships, so she went in the men's event and won silver (it probably should have been gold)! She won gold in the Ladies events at the 1908 Olympics and also skated in pairs!
3. Irina Slutskaya - Because she's fab with the Double Beillmann and the unitard at Torino. Plus the fact she came back from a very serious illness and got back on top is epic.
4. Liza Tuk - At least 2014-2015 Liza, although I still think she's awesome. But her 3A was so solid for that one season and she won it all!
5. Katarina Witt - Amazing performer.
6. Zhenya Med - I didn't actually like her that much when she first started out, but she's really grown on me, and I think her programs are well-constructed - although sometimes the music selection leaves a lot to be desired!
7. Michelle Kwan - Amazing legacy, not to mention a 5 times World Champion. She also did a guest voice on
The Simpsons and that was pretty cool

8. Sonja Heine - Changed the face of figure skating, moving the focus onto ladies skating, which is pretty impressive.
9. Kim Yuna - Lovely skater and the record holder of SP, FS and total score for ages.
10. Carolina Kostner - Longevity and amazing artistry!
Alas I don't know enough about pairs really so can only give 5.
Pairs
1. The Protopopovs - Historic couple, Wikipedia tells me they came up with three death spiral variations! They also won their Olympic Gold medal at 32 and 35, respect!
2. G/G - the epitome of pairs skating, even today their programs are breath-taking, beautiful skaters.
3. Shen Xue/Zhao Hongbo - Despite the fact they were (unfairly a lot of the time) judged as not as artistic as the other pairs since the came from China they kept on competiting becoming World and finally Olympic Champions! They also attempted the Quad Sal Throw at Salt Lake was totally gutsy and Shen almost had it!
4. Aliona and Robin/Bruno - Aliona's obviously the star, but her partners are also incredible, Aliona has really pushed the limits in pairs skating and it seems she wants to continue!
5. Tatiana Volosozhar and Maxim Trankov - I was looking at their programs from when the first paired up and wow! They kicked butt straight away! Also their triple twist was huuuge.
(I also hope to one day add Katia and Harley to the list! They're all ready trailblazing!)
I know even less about Dance so here's my top three
1. Torville and Dean - Self-explanatory
2. Virtue and Moir - Their lifts are out of this world!
3. Davis and White - They had some great programs, the Bollywood one especially caught my eye!