Out of their current lineup I'd recommend the Nokia 6610 which is what I have now. I bought the phone in Sep 03, and at that time I was choosing between the 6610 and T610 which were going for the same price ($149 for "existing customers in good standing.") Most people thought I was nuts for giving up the camera, better polyphony, bluetooth etc. and the much nicer design but I was just tired of Sony Ericsson's tending to be unresponsive and slow.
My previous phone was the T600 which was sooo tiny but full of problems (poor reception, slowness, a tendency to freeze, and it took forever to pick up a signal after leaving an elevator etc.) and I wasn't confident of the T610 being much better. Apparently some of the issues have been resolved, but not all do, and friends tell me the color screen sucks - poor viewing angle and "banding" on the screen.
I guess if you can live without the camera, bluetooth and fancy ringtones

the 6610 is better at doing what it is able to. That said, the 6610 does have some flaws, but they seem to be minor in comparison to the T610's
[This message has been edited by inkoherent (edited Mar 14, 2004).]
[This message has been edited by inkoherent (edited Mar 14, 2004).]