I had an Accord for a while, but rising gas prices ($3.50 at the time) pushed me towards a more economical car. I settled on the Yaris for the fuel efficiency and cost; I get around 37 mpg on average, mostly highway driving (35 mile commute each way to work). It is a very basic vehicle, but it suits my needs just fine. I opted for the MP3/CD player which was well worth it. The AUX jack in the center console is very useful, but the placement (right below the shifter) is a little awkward. The car looks quite small on the inside, but my friends comment on how much room there is on the inside (more than they expected, at least).
Fuel economy, cost, MP3 compatibility with CD player, AUX jack, center mount dash widens visibility and works great with window mounts (satellite radio, GPS, etc.), handles well on the open road, tons of compartments and cup holders.
Gets beaten around by crosswinds, interior plastic scuffs easily (particularly with manual windows), poor placement of AUX jack, no interior controls for side mirrors, cruise non-standard, road noise is a little loud.