Gotham has a lot of rich people but who's the richest? Is it Bruce Wayne or someone else?
I'm mainly looking for answers based on the comics but answers based on other Batman stories are ok as well.
According to the DC comics database, yes, Bruce Wayne is the richest man in Gotham City:
Kaiyo has stripped both Batman and Superman of any memories of their former lives. Having since learned that he is the richest man in Gotham City, Bruce Wayne is intent on taking advantage of it. Naturally, Alfred is concerned.
"Gotham Cable News", a fake website set up to promote the movie The Dark Knight, confirms that this is also true of the Nolan trilogy's universe:
Where does the richest man in Gotham move when his house burns down? For Bruce Wayne, the answer was easy - find the priciest luxury tower in town and buy the entire top two floors.
The script for Batman: Year One agrees:
The 25-year-old heir to the Wayne millions declined to comment on his return home after 12 years abroad. We'll keep you posted on Gotham's richest and best looking native son.
The website DCAU Resource goes even further, and claims that Wayne is not only the richest man in Gotham City, but also the richest man alive:
Gotham is famous for being home to the richest man alive, Bruce Wayne, and the city's resident protector, Batman who both technically live outside of the city.
The Essential Batman Encyclopedia says that Bruce Wayne is the seventh richest man in the world, with liquid assets amounting to roughly $7 billion U.S.
This figure is based on the Forbes Magazine list of the wealthiest fictional characters in the world, which apparently used the Nolan trilogy exclusively for its data. However, this site puts the number much higher, at well over $25 billion U.S.; this disparity is surprising, as the second source used the same material, but came up with a drastically different number.
I wouldn't include this if I didn't have the more canonical quotes above, but a user on Comic Vine makes a pretty strong case for Bruce Wayne being the richest man in Gotham, and one of the richest men in the world:
Bruce Wayne is technically a Trillionaire with billions in liquid Assets.
He literally owns something like 1/3 of Gotham's land, some of the most valuable land in the country, before NML and after he owned all that land plus made tons of cash by investing in all the businesses he financed. That's without considering the Wayne Manor and every thing in it. Wayne Foundation, Wayne Enterprises, and all the various other subsidaries and shell companies he owns.
The only people that can match him is Tim Drake due to technically owning all that stuff as well plus his own millions he had before and the investments he's made, but that depends on your outlook of that. The other person is Ra's Al Ghul who can only compare due to being alive for so long.
Imagine if someone owned 1/3 of all the land in New York, 50%+ of all the businesses, and something around 1/2 the buildings. That person would be worth in the Trillions and that is what Bruce owns, not counting anything else