Seems like every time you do a Google search for WordPress themes, you get the same little mix of sites, most of them Smashing Magazine. You can find some good themes there, but there are also some great and free themes that are really hard to find.
Well, the first place I was going to link to was Deluxe Themes, but they seem to be down right now. Hopefully, that’s not “down for good” because they really have some neat stuff. I would bookmark it and try again later if it doesn’t work right now. They’ve created some very complex magazine themes and even a theme that looks EXACTLY like the People Magazine site. One issue with them is that their themes invariably create a lot of databases on your server, so they are a little more bandwidth intensive than the average theme, and if you can only create a limited number of databases with your host, you may want to avoid them, or even if you are just on a shared server they may be a little rough.
Another good spot is BustATheme. Greg Johnson has created several unique themes, two of which can be used to make your index page show posts in a calendar form. I also like his News CMS theme, which is very clean and offers something that the vast majority of magazine themes don’t offer: no need for putting freakin’ pictures with every damn post. I mean, most of us are bloggers, not photographers, so why every other magazine theme out there expects you to put photos with every post is beyond me. If you’ve been looking for a clean CMS magazine theme that doesn’t require you to add photos all over the place, check this one out.
Themes Junction is a place that provides an absolutely massive quantity of unique and totally free WordPress themes. I’ve pulled several off of there, and they all worked fantastically. The only problem with them is that you are almost overwhelmed with options, but they have pretty good search and navigation features.