Thai Basil - a great lunch place--fast, plenty of seating, tasty food, and very inexpensive
House of Kabobs - This place has the worst location (alley end, facing parking lot) and as a result tends to be empty. However, they make some really good food including a great eggplant dip and yummy rice, as well as some unusual specials that you don't see at other middle eastern restaurants.
Dish Dash - When I worked at Yahoo we'd visit Dish Dash all the time. Food (mostly kebab/rice) is delicious though a bit pricey for lunch.
Turmeric - I've eaten there only once; it's an Indian buffet with some Indian-Chinese food. I'm not a fan of Indian buffets but this one had good quality food.
Phuong Thao - Vietnamese food. Don't get the pho here; it's not a pho restaurant. Dishes are hit or miss, need to visit a few more times
Il Postale - Really like the pasta here, probably too pricey for frequent lunch
Bay Leaf - Indonesian? Thai? Went to here once. I remember it being hit or miss. The main special dish, some kind of fish wrapped in a leaf, was quite good
Gumba's - reminds me of a casual east coast Italian place
North of Downtown
Sushi Club - my favorite sushi place in the Bay Area. It is tiny and run by two Japanese people, but the food is spectacular and the fish quality is about as good as it gets around here
Gombei Bento - owned by the same folks as my favorite Japanese restaurant (Gombei in Menlo Park), serves mostly takeout boxes of non-sushi Japanese food
Seto Sushi - one of the better traditional Japanese restaurants in the Bay Area
Sunnyvale Cafe - A tiny, tiny Middle Eastern restaurant, serving possibly the best mini meat pies in the world. A bit slow since it's run by two people, but definitely worth the wait. Also excellent hummus and baba ganoush.
Taqueria Latina - Cheap and tasty tacos, though not nearly as good as Rincon
South of Downtown / El Camino
Kabul - Afghan food. Probably my favorite restaurant in Sunnyvale, though i've never been there for lunch. I think i get two leftover meals out of one dinner there.
Adamson's French Dip - You know this one.
Pho Nam - My favorite pho in SNV. Pho Quyen nearby is also good and does sandwiches
Garcia's Tacqueria - best burrito in SNV
Old Siam - great Thai food, but the place is a bit strange
Dim Sum King - I've heard they have good take out. Haven't tried it yet
Taste Buds Indian - hidden away in a run down strip, kind of run down itself, but amazing food. I really like their fish curry and lamb saag, and their onion flatbread is even better than Taiwanese green onion pancakes. They have an odd specialty of a vegetable called "Gongura" which you definitely should not try unless you like lemony sour medicinal food. Haven't tried lunch there
Madras Cafe - Another good minimalist Indian restaurant, my favorite dosa place. Saravana Bhavan is a close second, and they have this awesome buttery cream of wheat dish
Shanghai Flavor Shop - famous for one dish, the panfried soupy pork bun. Really good, but everything else is sketchy
Giovanni's - the best hoagie you will find in the Bay Area. The secret? Using fresh rolls from a Vietnamese bakery (since you can't get fresh Amoroso rolls here). Also the best pizza in SNV
Palace BBQ - you know this one
Cam Hung - if you want more authentic Vietnamese sandwiches than Lee's
Windsor Fish and Chips - Taiwanese steam table food. Never been here even though I lived across from it for three years
St John's - burgers and beer