A list of components is one thing but to me there's another list and that list is what you should spend your money the most on depending on what you like out of your computer.
If you're a gamer you want to focus more money and emphasis on the graphic card(s), followed by CPU and Memory
If you're a developer whether it be programming or let's even go as far as multimedia production for stuff like 3D modeling work and stuff; you want to go with a higher end processor first and for most then a higher memory amount than most. If you do audio or 3D work you'll obviously have to go with a professional sound card/video card for that type but that's only natural that you leave a budget for those things.
If you're an enthusiast and you want the ultimate power house workstation that does everything, well you get the best of what you can afford, but usually that means you get everything you want and you don't mind spending the money.
But to me the 3 big things you NEVER SKIMP ON are:
1. Power Supply
2. Motherboard
3. Processor
I'll tell you why those 3 things you should never skimp on and why in that order.
1. The Power Supply, it provides your computer power, it's like the blood to your computer. You want a strong power supply to deliver the consistent clean and reliable power that will never give out on your computer. Let's face it, do you really want your computer to blow up because you got saved say $50 bucks on buying Brand Y over Brand X? Then when Brand Y's PSU blows up and ends up frying say your motherboard or worse your entire computer? I've seen it happen to others. I always get the PSU that will give you more power than you'll need so you have some headroom for future upgrades. Always think ahead and ask what do I think I might do later with my computer in terms of potential upgrades? Example getting a PSU that has enough power to support say that extra graphics card for say SLi/Crossfire, maybe you might want say that 2nd or maybe even the 3rd card down the road because all you can afford now is the one card.
2. Motherboard, I always like a motherboard that has a lot of functions/options, and spending a little more early is like an investment. You might not need it now, but who knows maybe next year or the year after you really did ended up needing that extra 2 SATA ports, or those extra 2/4 DIMM slots for more memory, etc... or whatever it is. It's better to spend say the extra little bit more like the extra $50 or so vs having to buy another board that will suite want you want later down the road, or worse having to upgrade a lot of things later down the road. Also it's a bitch to take everything apart and pop in a new board and redo everything, takes a lot of time to clear it all up and put it all back in with a new motherboard swap.
3. The Processor runs everything, it's the heart of the computer. Always get the best processor that you have the budget for that suites your needs at the price you can afford. It's never good to buy another Processor later down the road only if you had say you spent that extra little bit on the better one. Or if you end up doing that then you have a spare Processor which only means you either need to sell the old one or you might decide later you'll buy some cheaper parts to build another computer which ends up costing you more money.
Everything else you can easily buy later on and upgrade easily without too much work and overall won't effect the general power of your computer, unless it's something pretty big like say a graphics card for playing games but generally a Blu-Ray drive, or a HDD or SSD or faster memory isn't going to be big vs components like the Processor, Motherboard and Graphics cards. All those items are cheap, and you can always get better later and their easily plug and play type of upgrades you can do later down the road.
Let's face it. It's easier to upgrade a graphics card, ODD, HDD/SDD than a motherboard or even CPU, mostly because it's plug and play. Replacing a motherboard/cpu there's a lot of work involved like taking apart pretty much the entire thing or most. Not really fun, can potentially cause issues if you mess up.
the above is all assuming you picked a case that you're happy with and that you don't see yourself wanting to upgrade to a bigger/better case, cause that's a lot of work moving a rig to another case because you decide that case you don't like because of size, color or whatever.