By no means personally definitive, just a quick hodgepodge of some of the scenarios I have enjoyed the most, especially in the last few years...
DB130 Tigers And Flames
LSSAH 21 The Brickyard
BtB8 Steel Inferno
BFP 32 Slaughter At NanYaun
FT55 Finnish Blitzkrieg (still my favorite Finnish scenario)
FT106 Counterattack Along The Danube (Holst at his finest)
FT170 The Road To Juniville (a modern day classic, IMO)
RBF 24 Meeting Again
RBF 43 Blood Factory (great use of the RB map)
DB002 Sochaczew (the first DftB scenario I ever played, and still my personal favorite)
Honorable Mention: EVERY scenario I've played from Armies Of Oblivion (have played all but two, IIRC), a real tour de force from Martuzas.
Classic Status: ASL75 Strangers In A Strange Land (small and simple with a few smidges of chrome, I just really enjoy it)