I've used Sony Vegas 5.0 and I highly recommend it. Though it's not very expensive, you can do things that other low end video packages simply can't, such as advanced compositing, velocity envelopes, and colour correction. The way the Sony package handles keyframing is simple, intuitive, and amazingly powerful. The chainable effects plug-ins are incredibly versatile, you can insert them on a clip, a track, or at the output. There's also a bunch of user forums that are very helpful when you get stuck.
I've used Premiere Pro, but I was a little underwhelmed. Since this is an Adobe product, it uses the standard Adobe UI which I find annoying and hard to set up, the Vegas UI was written from scratch as a Windows app and it shows, you can reposition, resize, and dock windows and toolbars in the manner you've come to expect from Windows software.
The Sony product also excels when it comes to rendering. With Premiere Pro, I found that even the simplest effects needed to be rendered for them to play at full speed. With Vegas however, you just start a (say) five second loop around the area you're applying the effect, then adjust the effect parameters as the clip plays, and the output reflects your adjustments in real time as you make them. Lovely.
The audio module in Vegas is best of breed as well as this was originally a Sonic product that Sony purchased a few years ago. Vegas 5.0 also supports network rendering, you can send a part of your movie to another machine on your network for it's final render while you work on a different part on your local machine.
[edited to add:]
I'm not sure if you're aware of this or not, but you can download a 30 day trial of the full bickie version of Vegas 5.0 from Sony's web site.
