I'm a little surprised U. of Colorado wasn't mentioned with LASP (Lab for Astrophysics and Space Physics) and closeness to very good Solar Physics group at NCAR and gov't scientists at NIST and NOAA. Nobel Laureates amongst this group, including very recent ones. Also Southwest Reseach Institute is very strong in planetary physics. Many NASA Principal investigators among this group.

If you are interested in planetary physics AZ State is good.

And both CU and ASU are known to be great party schools! You obviously are independently wealthy if you are interested in studying astronomy as there is little chance of making any $ in this field. Might as well be exposed to some really good partying, too, if you want to waste your life doing this.

I second the other choices, too. Rice is particularly good. U. of Iowa is very good in Space Physics. SUNY is doing some good stuff on some of their campuses. I also like UCSD. and maybe UC Santa Clara banana slugs near Lick. Notre Dame has an up coming group and several Canadian schools are good. Cornell has a good groups especially in Radio Astronomy. I presume you are english speaking and wouldn't be interested in going to Russia, but they have some world class stuff there.

All these schools can be highly competitive with many huge egos abounding and in the graduate schools there is lots of campus politics and fighting amongst each other for positions, reputation and credit for achievements. If you just want to take a few classes in astronomy, I'd recommend trying to study one of the basic sciences like math or physics or even electrical engineering and then take some classes at a decent community college with a friendly, dedicated english speaking teacher. Many lower level classes in the big schools are taught by foreign graduate students who are difficult to understand; sometimes teaching out of notes that aren't easy and using math you haven't seen before in other classes.