This will be my first time so I guess I need to ask more questions. Ill be playing the latest and more demanding games constantly so I need a machine of that caliber so...
-top 5 parts most of my budget should go to?
CPU, GPU.
Which should get more than the other depends.
Fast-paced games will make mostly use of the GPU, but can take advantage of better CPUs, usually. They're after high framerates, and a CPU bottleneck cannot be gotten around so easily as a GPU one, so they tend to be lighter on the CPU, at any given time. IoW, going from a $175 to $250 video card would get you more than going from $175 to $250 CPU.
Strategy, from Starcraft II to Civ V to Dwarf Fortress and clones, will make use of mostly the CPU's top few speeds, including the Turbo speed.
Photoshop will use all the CPU you can throw at it, in speed or cores, and once you're beyond IGP, the GPU practically ceases to matter.
The rest is too dependent on other factors. An SSD, FI, costs more if you want more space. So, how much of the budget should that be?
More than anything, you just want to not skimp or overpay for the rest. But, CPU and GPU are where you pay more to get more performance.
which brands should I prioritize?
Varies.
Mobos: Asus, Gigabyte, ASRock, MSI, Biostar, Foxconn, Intel. My preferences go in that order. ASRock and MSI sometimes do a bit more penny pinching than I would like, on their lower-end boards, though they're higher-end boards are as good as anybody else's.
Video cards: Asus, Gigabyte, MSI, eVGA, and Sapphire (used to be ATI's OEM, back then they had branded cards) are generally top-notch.
SSDs: Samsung, Plextor (Liteon are Plextor), Crucial, Intel.
RAM: Crucial, Kingston, A-Data, G.Skill, and others...
16, as 2x8GB, with room to expand. Just make sure to stick to 1.5V rated RAM, or lower. With a new Intel CPU, faster RAM nets you so little as to not be worth bothering with.
what type of cpu/gpu/mobo should I be looking at?
Brand spanking new LGA1150 i5-4xxx, i7-4xxx, and E3-12xxV3, paired with an 8-series motherboard. With overclocking in mind, that leaves the i7-4770K and i5-4670K.
Is PcPartPicker my best resource and if so should i use them to pick my parts and refer to here to make sure I get the best bang for my buck?
Best single resource? Yes. However, due to shipping and combos, it is often better to by from only a couple places, usually Newegg and Amazon. My method is generally to price everything at Newegg, find good combos or promos, and then see if Amazon has any non-combo items cheaper (the last step I skip when I'm not actually buying--like in threads like these--since it takes so long to search/browse Amazon). Amazon often has combos with savings on PC parts, too, but I find it too annoying to look for them if they haven't been posted in a deal forum/blog somewhere, due to their website's clutter and all.
I'm definitely going to go for
-main HDD being SSD
-1 or 2 HDD that are sata to store games and movies
When looking at those, you won't be able to tell the difference in performance betwen a Samsung 840, Plextor M5, Crucial M500, or Corsair Neutron. Samsung has been pricing aggressively, recently, so you'll see the most recommendations for theirs.
-some way to connect to a flatscreen tv to watch movies
-overclocking and underclocking if possible
Underclocking may be hard to find (really, just under
volting), but you really just need to get an Intel CPU, and good cooler, today (such as the one SF linked). You can get 95% of what you could have gotten from underclocking by adjusting the max processor state in your power settings.
If you have an HDMI on the video card, which is hard not to get, today, it will hook up to your TV. Many TVs also have DVI, too.
I want something high performing for gaming, photoshop is a hobby, and watching movies and shows will happen as much as gaming. I'm very very new to building a pc so at first I thought my choices were okay but I need to be enlightened.
Photoshop and games are all that will be able to really stress your computer, for now. You will be better off, IMO, putting more of your budget into a monitor, then getting the rest with what's left over, than going big. You will probably still have enough of a budget for a i7-4770K CPU, if you drop your video card down a little, like to a HD 7950.
Since you haven't ordered yet, wait a few days. Haswell just came out, is a decent step forward, and is in stock everywhere. Availability is likely going to be chaotic. But, it is faster, idles lower, and costs only a hair more (almost no more, if you were already going to get a Z-series motherboard).