I am instantly thinking of examples of architecture I don't like, sadly, such as the pickle and testicle buildings in London.
For examples of great modern architecture, I think first of Maya Lin's Viet Nam War Memorial for many reasons. I also think about I.M.Pei's glass pyramids at the Louvre, although they are better appreciated from within than without (his intent?). You must visit the Guggenheim Museum of Art if you haven't...it is a giant spiral on whose walls hang art of all kinds that you can see up close, or from afar, if you look across the eye of the hurricane, so to speak, to the other side - a surreal experience. The doughnut-shaped Steinhart Aquarium in SF is another marvel - you stand in place and watch schools of fish swim at high speed around your head - and the Monterey Bay Aquarium is another genius structure. All of these examples are interactive in some way or other.
I think a person could go on about this all day long, but let me end with what I consider the all-around best architecture for dwellings: the Arts and Crafts (Craftsman) bungalow. These can be found coast-to-coast in any city where people built houses around 1915. Every single one of these homes has astonishing natural light from an abundance of large, sometimes embellished, windows (even in the closet, where I found out the hard way that this can fade clothing and is bad for wine). There are always tons of built-ins, like china cabinets, linen closets and shelving, and our bungalow in San Jose near the Rose Garden district is the style with a huge porch running the entire front of the house that we used as a (supervised) playroom for our kids, after my father-in-law built a special gate for it across the top stair. You can safely say that bungalows have an open floor-plan, because the rooms are connected with huge openings (rarely arches) rather than doors, although pocket doors are common. Ours also has a coved ceiling, is entirely lathe-and plaster, and features glass-knobbed and French doors inside. Of course, the floors are wood, and expect to see a central metal heating floor grate. These houses are more than sturdy - the walls are incredibly thick and substantial. There is woodwork everywhere, and not always exactly sophisticated. Our woodwork was painted white throughout, and this added a beautiful, bright ambiance that we loved. We miss it. Bungalows are happy, healthy places. They were built with respect for man and nature, both.