You need a video card with capture capability, or a stand alone capture card. The ATI AIW works fine for this.
The question always comes down to how much do you want to spend if you need to buy and add-on card or stand-alone device.
I have a Leadtek Winfast 2000 Deluxe available at Newegg for around $50 (?). I see they are out of them at the moment. I think the Expert version is similar.
http://www.newegg.com/app/ViewProduct.asp?submit=manufactory&catalog=47&manufactory=1280&DEPA=0&sortby=14&order=1
I have converted both from an analog camcorders and VHS with good results. At work we use Canopus, but they are very expensive.
There are other brands such as Hauppauge, Pinnacle, ATI TV Wonder etc.
By far the Leadtek is the most popular and at the time I bought it IMHO the best for the money and will do what you are wanting to do. Do your homework since I've had mine for quite some time.
What are your hardware specs? That makes a difference. If you have an Intel with Hyperthreading, beware that the ATI card had problems, but I would think they likely fixed it by now.
Again, the bottom line is, how much you want to spend, which translates into video resolution.
Edit: the Plextor AV100U posted by gowhitesox from Best Buy is a good price, and is an external model. I'm not real familiar with that model, but looks like it may be a good choice for that price for your application.
Good luck.