We have frequented all of the Indian restaurants in Madison (that we know of) and while I have nothing really negative to say about any of them I will say that they all feel kind of the same. Buffet of assorted Indian specialities and classics (for instance-samosas, which are a real highlight for me), kind of awkward service, attentive filling of the water glasses, and a bit on the pricey (overpriced?) side. I guess I would give Maharani a bit of an edge because of its location- very close to the capital- and most of the other Indian restaurants are a bit out there (though, Flavor of India is one exception). Check out some of the reviews they have on their website- I could get behind most of those comments but I wasn't inspired enough to get all crazy.
Sometimes you just want Indian food- and so Maharani is a great option if you're in the mood. Nice convenient location, buffets at lunch (and brunch on the weekends), and a overly animated websites (seriously, go check it out).