How "urban" does Houston feel?

Dumb question so bear with me please.

I've always wanted to live in a big city – the bigger the better. If my career weren't a consideration too, I'd pack up right now and move to NYC and take whatever job I could get.

But I'm also an engineer and my dream has always been to work at NASA, so to find a middle ground between those two desires, I've had my eye set on Houston. I was wondering if anyone can subjectively give me an idea of how much of an urban, big-city feel Houston has? I know it has a big population (both metropolitan and official city limits) but I also know the city is pretty spread out. If I'm looking for a big-city vibe, how good of a fit is Houston?