"MOST"
Sorry I somehow missed the CAPS in your question.. "most" is the top item in my long list.
Field proven (lots of happy owners), Reputable manufacturer and consumer friendly retail outlet.
Battery capacity.. (More bigger is more better)
Rugged and professional appearance.
I like fast scanning radios..
When I scan I want to get from beginning to end and do it again at warp speed.
I like radios that easily and quickly *decode* CTCSS and DCS.
This whole business of slowly "scanning" for tones seems crazy.
I don't care all that much about color displays.
Visibility in all lighting conditions is more important to me than color.
Sensible non cryptic screen layout.
I want a reasonable number of characters for my descriptive channel names.
I hate memorizing acronyms.
I want to personalize my screen in every way possible
Bluetooth is very sexy to me.
BT would weigh heavily on my decision to decide between competing models.
Connecting speaker and mic to my motorcycle helmet BT system... A BT PTT remote.. Programming the radio from my cell phone.. Yeah that would make a radio hard to pass up for me (although my pockets are not very deep).
I personally don't care at all about extra frequencies (except for NOAA).
FM broadcast radio, civil service and air band don't interest me. (Not sure if I am normal.)
Flash light function will never get used on my radios.. I disable if possible.
I might think of some more later..