A friend of mine got the Xperia L for 17k. Another good phone is the LG Optimus L9, although except for a larger screen, all other specs are better in the L.
Someone mentioned features like Full HD recording and Multi Window as great features.
As a L9 user myself, i would say the best features of my phone are,
EXCELLENT Tocuh response, really nice, even the faintest of touch works, so nice to use.
Clean UI, people usually mention HTC when it comes to UI, and even Samsung Touch Wiz, but i really liked the LG interface, simple, uncluttered.
Screen. No it isn't AMOLED or having XYZ Engine, but the screen is excellent, bright , natural colours ( hogs battrey though )
My point is, you can list all the specs, but the actual requirements are the most basic ones.