I'm looking for a really good and reliable web host. Any suggestions?

It really depends on what your needs are. If it is for a private self web page I'd recommend some shared host such as Dreamhost. I only recommend Dreamhost because they usually have awesome deals of like $10 per year. But if you need a lot of power or need to do certain things and need root access I'd recommend some sort of VPS such as vps.net. If you add details or let me know more of what you're looking for I can better recommend some solutions.

It's my own personal web page, but I want to be sure the server can support apps like node and pylons(a python framework). Is dreamhost good for this?

Dreamhost will allow you to install node and pylons, that shouldn't be an issue. Where you might run into trouble is the fact that they don't allow network daemons so you can't connect to any process (such as node) from an outside connection which would ultimately defeat the purpose. So in your situation I'd look at some sort of VPS solution. There are a lot out there, the one I'm familiar with that I mentioned earlier is vps.net they aren't too expensive and you have a full virtual console to work with.

I believe HostGator is a good choice. I would really look at them. They use wind-energy to power the data centers.

Hostgator and GoDaddy are good and reliable.

There are ton of them, it depends what you need or what software you are going to run I have not used Go Daddy in a long time thery have good support but so do a lot of others ant half the price with less restrictions. If you are going to use Joomla then siteground (http://www.siteground.com/), other than that I use host gator and host monster for shared server accounts and compare when needed for dedicated hosting.