They were all really neat and fun to visit, but I'm not going to write about all that standard touristy stuff. Instead, I'll note a few things that intrigued me.
In the following, it may be useful to keep in mind that Rs 50 (INR) is approximately $1 (USD), So, Rs 1000 is $20.
Firstly, the driving. It is crazy. The roads are one-and-a-half lanes wide, and we are in a small bus, barreling down the road honking every few minutes to let vehicles know we are going to pass or to tell oncoming vehicles not to hit us. And I use the term vehicles rather loosely. This covers anything from dogs, donkeys, cows, horses, camels, humans, bicycles, motorcycles, rickshaws, cars, busses, trucks, and in some places, even 18-wheelers. All sharing a narrow road passing eachother frequently.
Depending on the city, traffic lights seem to be entirely advisory. In Delhi, they were followed, but in Agra, I can't say I could figure out how to tell which lights were to be stopped at and which were to be ignored.