I think building your own has more advantages over prebuilt any day, consider this...
- OEM's tend to put cheaper products in your computer (cheaper ram, budget video cards, etc..)
- Harder to upgrade, especially if it's a propietary case...
- The extra software can sometimes be a DISADVANTAGE, especially if you don't want it at all, period, also takes up space
- If you really wanted bundled software, you can get packages for like $15, and as someone else said, you can grab full version OEM OS
- Support is only there for so long, and only if you pay an arm and a leg, knowing your own components helps you and your problem solving
- I've heard phone tech support is abysmal
- If were talking price for price, I think you can still beat out OEM's
- No matter what they offer, sometimes they still don't have what you want in there "Configure System"
- If you wanted to install your own OS, and had a problem, OEM tech support usually won't support you unless it has original pc configuration
- Dell only does Intel, so if your an AMD fan...
- I agree with busmaster11 and barrei
Anything else I forgot? Basically, you name an advantage and we can either disapprove it prove a better. The only advantage I can see is when your administering a large amount of people, but even then you can go to mwave.com or anyplace like that and they will build YOUR computer with the RETAIL components YOU select. But that probably doesn't have any bearing since your topic is "Dell vs. building YOUR own.