Dahi vada, gulab jamun, and kheer are killer. If you go for the buffet branch out a little and try their offerings other than standard chicken tikka masala/palak paneer...while those are both very good, it's worth your while to try things like the kadhi pakoda (a Punjabi curry consisting of chickpea dumplings in yogurt) and the chili chicken (an Indo-Chinese dish with chicken in a fiery sauce), as well as goat curry. Goat isn't scary--it tastes a lot like lamb, though a tad bonier. Sometimes they have idli and hakka noodles too--worth a try! I do not like their tandoori chicken at all--always too dry for me!
Service is a little brusque but I'm okay with that. They show music videos from Bollywood movies at least during lunch (haven't been for dinner since before their extensive renovation), which is a lot of fun. They also do an extensive catering business and have an attached banquet hall where I always see people having engagement parties. They also provided lunch for the Indian delegation to the G8, which should say something about Taj Mahal's place in the Indian food community in Pittsburgh.