We have investigated the sub-milliarcsecond scale structure of 41 γ-ray bright blazars with the VLBA at frequencies of 22, 43, and occasionally 8.4 GHz. All of the blazars have dominant, unresolved (less than 0.1 to 0.2 milliarcsec) cores, with the exception of 0954+556, which has no structure apparent on scales less than about 1 milliarcsec. Some have prominent jets, others show only faint secondary components or no non-core structure at all. Apparent velocities have been measured for 13 sources. These range from no detected motion to > 25c.