A lot of issues have been raised here, and I thought it might be worth separating some of them and putting some facts on the table.
Batteries: If you get more than two years out of them, consider it a bonus. Not specifically a fault of Dell, HP, Apple, Toshiba, Panasonic, Acer (although ACER is focused on the cheapest of the cheap in everything). It is the battery technology. The battery will only function reliabily for x number of recharges. Changing laptop brands will not help here. Better to spend more up front for 6 or 9 cell battery, rather than 3 cell battery, and reduce the frequency of recharging as well as extending the time available on battery.
Hard drive issues: Probably the least reliable item in your laptop or desktop. It is still mechanical (for most). Laptops get dropped, banged around, abused. If these things happen when the laptop is functioning, problems are unavoidable. The tolerances and spaceing inside these devices are critical. Now, gettinga military hardened laptop improves this situation, but I do not think anyone here can afford the price, or wants to carry the weight.
Motherboards: The designs here vary by brand and by model. The electronics (the chips themselves) are pretty robust and shoold last forever. Ooops! Ignoring what is called infant mortality. But these failures occur very early, definitiely in the first couple months of usage and should be covered under warranty. The real devil here, for long like is the motherboard itself, and the solder connections. Quality control and physical design are critical for long life. All, 100%, of these boards are assembled offshore. Some in factories owned by the brand, most contracted out to other copanies that do just this. This is where board or solder contaminated with sulfur for example, will grow crystals that will short between traces on the board. This is a quality control issue as is the temparatures and time when the vairous layers are bonded together. Now, if we can't keep contaminated food for our dogs, and our people, from coming out of China, how the hell can we expect tham to pay attention to electronics produced there? How can we expect them not to take every shortcut and cheaper material they can find?
The Dell product is reasonably reliablle and durable product. As is HP, Sony, Panasonic, Toshiba, and others. I would not purchase an Acer, eMachines, or several others. In general, you will get what you pay for. Apple is unique. Its a good product, but priced way to high for what you get with one exception. If your work is graphics oriented and something other than casual or home photos, it is probably one of the best solutions out there. For anything else, it is just a place to spend more than you need to.