dont go for sensation, it has faulty issues like death grip on wifi and bluetooth signals, issues related to responsiveness of touchscreen that appear only a week after purchase, dust easily accumulates under the screen...
galaxy r & optimus 2x are discontinued,
moto atrix 2 has a decent enough hardware to play any app/game out there but the real problem is lack of developer support ( bootloader is locked, hence no custom roms for it )
otherwise if you feel nice aroung the moto UI ( and they've also promised the ICS update ) then go for atrix 2
Your best bet however would be to wait for Xperia P as i doubt Htc one S will be in your budget. i think it'll be priced around 30k
or you can simply wait for galaxy s2's price to fall .. its a great phone tbh