I, personally, use Astrology for Windows by Halloran. It's got most of the major cities of the world in its atlas, so that's always good, and it has a useful 'Here & Now' button for horary questions, just click the button (and then double-check whether it's DST or not) and BAM you've got the chart for that second. You didn't have to put in anything. A major advantage and time saver. There are really only two downsides. The first is that you can only save one chart, unless you pay for the software, so that downside can be easily resolved. It's just I'm too cheap. The second, much more major negative is that the only bodies it keeps track of are Sol, Luna, Mercury, Mars, Jupiter, Venus, Pluto, Uranus, Neptune, Saturn, Chiron,
Part of Fortune, and the North and South Node.
So, since it is that way (adding in the useless Chiron and not having the Quartet), I've also employed Astrolog. I have version 2.4, but I don't know if there is another version out there, I haven't looked. This program is much, much more complicated than Astrology for Windows. You have to input everything though, there are no short cuts. However, it can track all of those planets mentioned above, as well as the Quartet, Uranians, 20+ Fixed Stars, and even some other stuff I've never heard of. Also, if you know how to use it, you can get charts set up from other planets, as well as do harmonic charts. You can even do Vedic astrology with the sidereal system or even heliocentric astrology if that's just what you wanted to do.
So...uh...yeah...now I feel like an infomercial.
Buy now! :D
Or you could take the easy way out and go to astro.com, set up an account and go willy-nilly. You know, whichever.