We've flown the Yellow Aircraft Extra 300Ls (both the 60 and 120-size) and adored them. Stunning quality and looks, fantastic flying characteristics, etc make this series a must-have in the collection. Whether it's the best is debatable.... but they're beautiful birds.
For some video of the big extra in flight (complete with smoke system):
http://archive.ncsa.uiuc.edu/Cyberia..._extra120.html
and
http://archive.ncsa.uiuc.edu/Cyberia...xtra120_2.html
For video of the 60-size Extra:
http://archive.ncsa.uiuc.edu/Cyberia.../rc_extra.html
-Juhan