1

lenron
As you will soon learn, the regular tree dwellers have quite divergent views on Delhi. Some hate it with a passion and avoid it at all cost. They find the noise, the pollution, the aggression and the cupidity of its denizens distasteful. Others enjoy the greenness, the museums, the shopping and the sophisticated energy of the place.
I am one of the latter and never miss the opportunity to spend a few days kicking around the town.
I think the big trick is to stay out of the tourist ghettos like Pahar Gunj and stay down in one of south Delhi’s swanky enclaves like Gulmohar Park and get out into the town’s mouldering piles, quite green parks, funky art/shopping precincts and good eating that is to be found around about the place. Getting about on the metro with a little walking makes this cheap and easy.

2

Agree with the above, I always enjoy a couple of days in Delhi...

3

I live in Delhi and love it. It takes 3-4 days to see historical monuments and proper city tour. The guided city tour is just starts from Red Fort in old delhi and ends at Lotus Temple which included India Gate and Qutub Minar.
If you want to have a real feel of Delhi then stay at Pahar Ganj (crowded but cheap) and take a walk to chandni chowk, Jama Masjid and then eat at Karim's resturant (authentic muglai food). Red Fort has a museum, Raj Ghat (Memorial of Mahatma Gandhi), Old Fort and evening walk from President's house to India Gate.
Quotub Minar, Hajrat Nizamuddin Dargah, Lotus Temple etc and then food at delhi haat. If you want to buy cheap clothes then visit sarojni nagar market and Janpath Market.

You will fall in love with Delhi.

4

IMO Pahar Ganj does not give you a "real feel" of Delhi, it's a backpackers' ghetto, I
would only stay there if there is no other choice...

5

I personally like Delhi so much and I think if I will have to enjoy Delhi then might 2 weeks less for me. Bcs Delhi can never bore anyone. But I will recommend you a full day tour in Delhi is more then enough to enjoy.

6

Agree with zauberberg...