Great to see the number of reccos and detailed reviews from vanderb and others.
Kanua - Mangalorean food in a lovely partially-closed terrace sitting; this place always seems to be very popular with large families/groups. The only mistake we made was asking the waiters to suggest options, and ended up ordering too many similiar gravies. But, the fish and prawn (curries as well as dry - rava fried) are excellent. The bill came to approximately Rs.600 per head. They don't serve alcohol but you're allowed to carry your own beer for a small table charge. Kanua is in Sarjapura.
The Rogue Elephant - This is attached to the Ambara outlet in Ulsoor (near the Ulsoor lake), and has just a few tables with the owner doing the cooking. I think it can loosely be called European cafe style food. Everything always tastes so light and fresh here. Love their lemon-butter sauce in particular. The sandwiches are pretty good too.
Aangan, which has been mentioned by vanderb, I would unhesitatingly second. It remains one of my favourite Punjabi eateries in the city. Their chatpata arbi (spicy yam) is lovely. The thali is good value for money too, though I think it's only available for lunch.
Another good place is Road Trip in Indira Nagar - again, Italian/European but at more reasonable prices than you'd find at most places...
For Andhra food, my favourite is Nagarjuna - I like especially their outlet on Residency Road (near Mayo Hall). Of course, not meant for those who can't handle spicy food.
Not 5-star, but for Punjabi food in Bangalore, Queen's on Church Street is my choice. No-frills, but lovely food - spicy, but flavourful - not just chilli. And their Dal Makhani is one of the best things I've ever eaten at a restaurant.