The Mavic CXP33 is the best aero rim on the market in our opinion.   It features a tall narrow profile, but still uses eyelets.  So you get a rim that is light, stiff, aerodynamic, and very durable.  The CXP 33 is welded and then machined with Mavic's patented "UB Control" braking surface. The rim is 19.4mm wide, 23.6mm tall, and comes in silver in 32 or 36 hole, black in 28, 32, or 36 hole, or black 650c in 28 and 32 hole.  700c weighs in at 470 grams.