Been a lot of talented players:
talented in terms of raw power: safin, monfils, kygs, pete, blake, nadal
talented in terms of ball-striking - safin, Djokovic, Agassi, Nalbandian
talented in terms of improvisation - fed, kyrgios, monfils,
talented in terms of movement/athleticism - monfils, dimitrov, djok, nadal, pete, fed
talented in terms of feel - rios, fed, santoro, Mac, Murray, Arazi, Paire
Talented in terms of anticipation - murray, Fed
But if I have to pick one it's Fed - I tend to think players with head-light racquets have an advantage as they can more easily maneuvre and adjust late, hit the backhand overhead, flick shots more etc. No surprise that fed and kyrgios both have such set-ups.
Fed has incredible feel, ball-striking, have seen him hit literally every shot - backhand flick passes, fake drop shots, backhand overheads, tweeners, drop volleys, jump smashes, SABR etc. On top of that he can slide into defensive balls, rip winners from deep, serve with pin-point accuracy, and returns big servers quite well - anticipation.
Second? Of current era definitely kyrgios for me