For Vegan food in downtown San Jose there is a cafe on first street between Santa Clara and San Fernando that is called "Good Karma Vegan House". I haven't been in there yet, but it's always been busy at lunch time when I walk past so that seems like a good sign! There's also a Noodle house on Santa Clara street called Tofoo Com Chay that serves Vietnamese vegan food. I think it's somewhere around 300 or 350 E Santa Clara Street or something like that. It doesn't have much seating inside, but it's nice to have vegan Vietnamese options. Vegetarian House is a little farther down E Santa Clara street and it has vegan options, too. The atmosphere is a little odd because of the strong spiritual influences of the group that runs it, but the food is very good and even meat-eaters find things they like here (a very picky 4-yr old ate the "golden nuggets" and loved them, and she usually is picky even about what brand of chicken nuggets she eats). The staff are really helpful and friendly, too.
For other restaurants, we love Vung Tau at the corner of 12th St and E Santa Clara. It's one of the best Vietnamese restaurants in the bay area, has a nice atmosphere, and we love the food.
If you want really amazing food and don't mind spending a bit on it, Manresa in Los Gatos is incredible! It's highly rated, has an outstanding chef, and makes for a very memorable meal. We've only been once and it is still one of the absolute best meals I've ever had.
In a complete shift from Manresa, one of our favorite dinners out these days is to follow the food trucks! In the South Bay they've been doing "Moveable Feast" where a selection of the trucks will gather at a specific location throughout the week - Willow Glen, South SJ, Eastside SJ, etc. I think there's one in Menlo Park, too, but we've never made it there. If you get a chance to try the lobster roll or clam chowder from Sam's Chowdermobile, it's AMAZING! Chairman Bao, Louisiana Territory, MoGo BBQ, Treatbot, and Little Green Cyclo are our favorites, but we've still got a couple more trucks to try that look good, too. The link to their event page on Facebook is
https://facebook.com/MVBLfeast/events It's a totally different atmosphere from the restaurants, but the food is so good...and now I'm hungry just thinking about it!
Anyway, we live in downtown SJ and DH is a major foodie, so I've become familiar with a lot of the restaurants around here. As you can tell, we tend to favor ethnic places, so my recommendations will lean heavily that direction if you're interested. DH can point anyone to the best Afghani, North Indian, South Indian, Mediterranean, Vietnamese, Persian, Greek, Peruvian, regional Mexican, Thai, Japanese, Cambodian, etc. restaurants in town. They might be a tiny mom & pop hole-in-the-wall, but he's always looking for authentic and good quality ethnic food.