Looking at all suggestions, it reminds me buying my first car. I am been driving for few years now, its mostly in city like Pune and Mumbai. I think you as driver + owner should look for few things.
Driver:
Its imp for driver
a. how many times he is going to enter and exit in car during a day.
b. how much time he is going to drive
c. how many times he is going to change the gears and press the CLUTCH in a day.
d. how many hrs driving is in heavy traffic area.
One should not feel bit compromised about seating comfort, driving comfort etc. Looking at your height 5"10 Santro, Wagon R, Zen are the best options. If you are driving more in bumper to bumper traffic then Automatic tranmission is the best, else you may endup with knee pain.
Typically in small the quality of clutch is not so great and gear ratios are also small, which forces frequent gear changes >> knee pain. I think Santro AT is sold more than Wagon R AT. Also please check for ABS and airbags. ABS helps in city as well.
Owner: Looking at fuel prices, Look out for boot space to install CNG/LPG kits later. Zen may not help here. I know automatic transmission gives bit less FE but that can be resolved by CNG/LPG kits. The last point, Santro/ Wagon R can be driven with chauffeur in future.
Finally: Maruti, Hyundai, GM all make good cars. For new buyers in small car segement, the quality of service will increase as everybody is focusing here.