My wife recently got a Sony Ericsson Xperia Arc S (also known as LT18i). Pretty good phone, huge bright screen with really good battery life, running Android 2.3 and update to Android 4 (Ice Cream Sandwich) coming soon (guaranteed).
I think there might already be a newer version….
For Android I’d say:
* HTC are ok, I think, but too many models and they’re gone from the market way too fast (they release 1 model per week or so!), potentially making it very difficult to obtain accessoires or spare parts (such as cases or spare batteries);
* Samsung has, for us, an extremely horrible reputation for being liars and cheaters and not caring at all about support. Once you buy Samsung, you bought it – don’t expect any support at all;
* Motorola are very slow with updates, are (IMHO) mediocre phones, and quite expensive;
* with Sony, so far, we have had only (1) good experience…