Depends on what features you want and how much you would spend on it. In general price range Xperia X10 is a nice phone of Sony Ericsson.
Hi friend,, choosing phone products should be adjusted to the needs of your Nokia might be another alternative for you.
To my opinion and judging by my personal experience the best mobile is which has no glitches all the time. SE and Nokia are the best variants for this purposes, but even they have problems.
I think the Motorola Atrix 4G - Android is king right now. http://www.besttechnology.org/forum/viewtopic.php?f=33&t=490&p=897#p897
Right Now its Samsung Galaxy S2 and Motorola Atrix. Both mobile phones are best to buy. With latest android technology.