The following is a bit of read, but I hope this helps you out.
Top tier usually refers to the top sellers in a certain market. Although there's been some shuffling you usually the following manufacturers in the PC market: HP, Dell, Toshiba, Acer, and Apple. Lenovo is occasionally considered since they had a decent share when still owned by IBM; the market for Lenovo is still strong in the business sector. There are also brands under these manufacturers-- for instance Alienware was acquired by Dell in 2006 and represents their entry into high-end gaming PCs. Asus is also among the major manufacturers although their entry is primarily based on their component lines (motherboards, graphics cards, etc.) and netbook sales. When I refer to top I usually mean Dell and HP since they own the lion share in virtually every market category.
Although companies like Eurocom, Sager, and other integrators offer custom notebooks, the parts are usually sourced from an overseas manufacturer like Clevo and simply integrated with components purchased off the shelf. The warranty offered by these brands is usually poor and provided by 3rd party consumer electronic insurance providers. The turn around time to fix a custom part can be an eternity.
The reason I have any experience with this is because of the number of units that come through my work for eval. We have reps and FAEs that come down from each manufacturer to sell us on new server. They also send us notebooks for eval that usual head straight to QC so we can validate our products on each machine. The most common thing I have to say is the shear volume of graphics adapter we get from nVIDIA and ATI-- every time something new comes out we end up testing out a card that you'll probably never see on store shelves. I have a pile of them sitting in a corner in my office :P But I digress...
On newegg.com there is a tab for details where you can view the specifications of the product you are receiving. Unfortunately, newegg isn't a site that will try to sell you on a product through a marketing sheet. Newegg is spartan and geared towards techies that know what they want and simply want to confirm the specs before a purchase. Your best bet is to take a look at the item you are interested in, check the details to make sure it has what you want (for instance a dvd drive or blu-ray), and then read the reviews in the feedback tab. After you a satisfied you can copy-and-paste the exact model number into a search engine and look for a few professional reviews to validate your choice.
