So here are my thoughts as someone that has been out of Houston for 3.5 years (but goes back often). Apologize if dated
:
Restaurants:
Hugo's is great. Expensive, but great.
Backstreet,
Tony Mandola's Gulf Coast (the off the menu Calamari a la Mama is the best calamari you will ever have)
La Griglia -- May be my favorite restaurant in Houston for food & vibe. Lots of local celebrities eat here.
Vic & Anthony's for Steak which is near Four Seasons and Hilton downtown.
Lankford Grocery (is it open on Saturday? Bring cash!!)
Churrasco's (Argentinian food -- awesome)
Gravitas
Max's Wine Dive -- Wine bar with southern cuisine like Chicken and Waffles
Ruggle's Grill -- a little dated, but best veggie sides in town with huge portions.
As for Mexican, I think Chuy's is the most overrated food in Texas. But that's just me. I'd recommend El Tiempo (the Margaritas are dan-ger-ous) and Teala's. If you want to have a really good time, head down westheimer to a little hole in the wall called "El Patio." Their bar is called "Club No Minors" because, well, that's what it says on the door (you'll need a reservation) You can get all the same food in there, drink even MORE dangerous margaritas, and listen to the dirtiest mariachi band this side of Juarez. Please cab it or have a driver if you go there.
Brunches -- can't go wrong with Hugo's. If you are up for a wild start to your Sunday, though, check out La Strada. Don't know if it's the same, but it could get a little rated R early on a Sunday morning in there. Benjy's (at least 2 locations) is also a lot of fun with great food. Make reservations at all those places though.
Other "high end" fast food - Mentioned Beck's. Another cool place is Amazon Cafe on Kirby (which is to Churasscos what Pei Wei is to PF Chang's. A lot of fun and very kid friendly). Goode Co. Tacos on Kirby is much the same vibe.
Going out -- Washington Ave is the new "it" spot. My best friend is bar manager at Absolve Wine Lounge in the area, which I haven't been to, but I'll likely be there Saturday night. Washington is getting a bit too big for its britches though (hence the popular term, the "douchefication of Washington Ave"), and it's a little sad as they've run off all the famous live music venues on the street. I typically prefer some of the one-off spots in midtown, rice village, river oaks area. If you are looking for places to go in those areas, PM me. Downtown and Midtown have plenty of fun places to be at night. Just be careful. Midtown, especially, can be a bit squirrelly at night despite the high end condos in the area.