The Collaborative International Dictionary of English v.0.48:

Topflight \Top"flight\, a.
   unexcelled; of the highest grade; of greatest skill;
   exhibiting excellence; a topflight performance.
   [PJC]

WordNet (r) 3.0 (2006):

top-flight
    adj 1: excellent; best possible [syn: top-flight, top-hole,
           topping]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "topflight":
   arch, banner, capital, cardinal, central, champion, chief,
   crowning, dominant, first, first-chop, first-class, first-rate,
   focal, foremost, great, headmost, hegemonic, leading, magisterial,
   main, master, overruling, paramount, predominant, preeminent,
   preponderant, prevailing, primal, primary, prime, principal,
   ranking, ruling, sovereign, star, stellar, supereminent, tip-top,
   top-drawer, top-hole, top-notch, topping, tops