brother we were going through same confusion earlier, you can see my earlier threads for details.
Now what i can advise you from my experience is "IT ALL DEPENDS ON YOUR REQUIREMENTS". All of these three are good, but if want want to pick one, only your requirements can help you to make decision. Here i will try to make it simple for you assuming that you want a good safe family car for a long run.
GLI
Good Resale, Not so good on consumption infect 1.8 Altis and 1.3 GLI are somewhat similar in consumption. Bad power to wait ratio. Value for money a "big No".
City
Bad Resale, Good fuel economy, Nice Boot space, good acceleration, Value for money "NO".
Swift
Dont know about resale, good fuel economy, boot space is not good, filled up with all the goodies(DLX version), no need to spent a big amount on after market stuff after purchase. Value for money "Yes" if you are comparing it with GLI or City.
So if you are searching for a good family car for a long run use for your family Swift DLX is the best choice, the only drawback which i see i small boot space but how often do one needs it, and also if its second car in the family this is no problem then. So my advice will be to go for swift eyes closed you wont regret it.