I'm currently using two machines. My oldest is a Compaq Presario laptop which has 512MB of RAM, 1.8 GHz AMD Sepron processor and a 40 GB HD. It's running XP... basically a bargain machine which is fine since I typically just use it for web surfing.
My new machine is a Dell XPS 410. I just got it about a month ago and I'm very happy with it. I had Dell put in 2 GB of RAM, a 250 GB hard drive, an Intel Core 2 Duo at 1.8 GHz each and an NVidia GeForce graphics card. The monitor is a 19-inch widescreen LCD which was something to get used to after using a laptop for a year. It came with Vista Premium pre-installed but, I did a fresh install to get rid of the Dell "crap-ware". I then partitioned the drive and created a dual boot with Ubuntu. Linux, of course, runs perfectly... and Vista, of course, is filled with bugs. I also added a second hard drive which is 80 GB and has mainly mp3's on it. It's about 5 years old and has a 40-pin IDE connector. I had to buy a converter since the mother board only uses SATA. It was fun figuring out which jumper setting was the correct one. The instructions on the converter said to set the drive as "master" but, cable select was the only setting that worked. Anyway, I'm very happy with my Dell and use it more often than my Compaq.