I've stayed at the Riverwalk Embassy, Riverwalk Hilton Palacio, Riverwalk Home 2 Suites, Doubletree Emily Morgan.
Hilton has small rooms, but is modern. Breakfast downstairs is a nice buffet. Step right out to the Riverwalk, which is pretty. Pool is useless. If I'm staying by myself, and prices are equal, this is where I like to stay (breakfast and proximity to cutesy Riverwalk make the decision here).
H2S is functional, walking across the street to Alamo and Riverwalk. Grab and go food. Rooms reasonably large and kitchette setups.
Emily Morgan has character.

It's got nice views from the top floors. Doubletree buffet ain't bad. Parking awkward. Walk to Alamo and Riverwalk. Got upgraded to decent room, but the layout is a little weird, like old buildings are apt to be. But it's not a cookie-cutter hotel, if you like "charm".
ES has solid, newish rooms, breakfast buffet on par with most ES, I stay here more than the others but sometimes the price is oddly high. They started charging more for parking here, which is a bit high.
TDM