Great question! I personally have different favorites for different surfaces. But one of the most important things (for me) is how they treat the horses trusted to their care. It makes a huge difference for me to see them treat a horse like a friend and not necessarily as a business commodity.
One of the kindest Trainers I have ever seen bar NONE is Michael Matz. I love Shug McGaughy, Nick Zito, Bill Mott, D Wayne Lukas (even though many will accuse him of burning up horses), Malcolm Pierce (Canadian), Roger Attfield (Canadian), Mark Frostad (Canadian) and Carl Nafzger. I love listening to the old timers like H. Allen Jerkins, Scotty Schulhoffer was one of my favorites! The tales they can tell...
Some of the later Trainers I highly respect are H.Graham Motion, Kieran McLaughlin and Christophe Clement.
My favorite jockeys are Edgar Prado... I have followed his career since the early 1990's, the recently retired Mark Guidry, Shane Sellers ( retired for 2 years I think), Kent Desormeaux and Mike Smith. Mikey used to be known as the King of Saratoga until he broke his back there in the last week of the 1998 meet. Prado and Smith have the best sets of hands I have ever seen... they are just SO kind to all their mounts I have seen them ride. I like Calvin Borel, he is just so down to earth you have to respect the guy!
*** Addition: I can't believe I left out Barclay Tagg (and Robin Smullen)! This man has a pretty gruff demeanor, but what he knows about horses would amaze you! I know he caught a lot of flak for scratching Funny Cide when the weather conditions didn't meet his expectations, BUT he knew Funny Cide inside out, and he wasn't going to put him in a situation that might be detrimental to his health. He started out with Frank Whitely (of RUFFIAN fame), personally I think he got the gruffness from Frank...LOL! He and Robin are a team, and now Robin uses Funny Cide as her stable pony (he lives like a KING and is still going to the track so he's happy as you know what...)
I was thrilled to see Shug take 2 stakes races yesterday, and with his long time client Stuart S. Janney to boot! He took one at Churchill and one at Aqueduct... just a small hint here: keep your eyes on Alan Garcia as an up and coming jockey. He won't be flying under the radar for much longer!