Flight International - although it's a bit dear for a 6-minute read as WWW said. Plus it includes such features as UAVs or spaceflight which don't concern me (NASA having ignored my application again
).
Airliner World - the first 15 or so pages of airline news are worth the price (and quite useful in keeping
au fait with what's happening in the industry), plus there is some good photography.
Otherwise, a Jeppesen manual or the FCOM or the Route Perf Manual or
Focus if I'm flying with a training captain - if not then
Nuts or
Zoo or
Playboy 
will do (although the latter is no good for concentration
)
Cheers
