I will go with HTC due to their blend of Design Sense, durable form factor and affordable pricing. and HTC Wildfire S is Mobile of the year.
Xperia 10 is a 2010 mobile, This is the mobile I have and I bought it last year. Best mobiles of 2011 are Samsung Galaxy S 4G, LG optimus 2x, SE xperia Play, Motorola Atrix 4G
AS per my Opinion Samsung galaxy is the best and HTC desire is also good one till today, but i think if you want to more features and no budget limits then wait. I phone 5 is coming soon. it will be the best for 2011.