I have a DVD drive, but I leave it unplugged most of the time because I don't like it making noises upon startup/etc. When I need it I simply reboot and plug it in
More to topic, it's best to build on your own (you can hunt-down the best deals and assembling is fun). BUT in case you are simply scared as hell of touching expensive tech, I know quite a few people are, sites like NCIX and CyberPower offer building services + warranty for a relatively cheap price if you order everything from them.
Once you've outlined a budget, you should be able to get an easy recommendation for parts in any community/group that keeps up with tech and knows how to suggest well-balanced builds.
You most likely won't even have a budget at this point since you don't how much typical parts/etc cost.
Budget-friendly build that will run most games at medium settings:
MoBo: ASRock H77 Pro4/MVP [http://www.newegg.com/Product/Product.aspx?Item=N82E16813157302] -
$74.99
CPU: Intel i3 3220 [http://www.newegg.com/Product/Product.aspx?Item=N82E16819116775] -
$129.99
RAM: Crucial 1600MHz 8GB [http://www.newegg.com/Product/Product.aspx?Item=N82E16820148540] -
$49.99
GPU: Gigabyte GTX 650 Ti [http://www.newegg.com/Product/Product.aspx?Item=N82E16814125447] -
$129.99
HDD: WD Caviar Blue 500GB [http://www.newegg.com/Product/Product.aspx?Item=N82E16822136769] -
$59.99
PSU: Antec VP-450W [http://www.newegg.com/Product/Product.aspx?Item=N82E16817371045] -
$39.99
Case: Xigmatek Asgard [http://www.newegg.com/Product/Product.aspx?Item=N82E16811815018] -
$34.99
Optical: Asus DRW-24B1ST [http://www.newegg.com/Product/Product.aspx?Item=N82E16827135204] -
$19.99
Estimated Total Price - $540
Going all the way to a well-rounded beast that will eat through almost any game at high/max settings (absolutely destroying next-gen consoles), not to mention the PC itself will be snappy-fast due to the SSD:
MoBo: MSI Z77A-G43 [http://www.newegg.com/Product/Product.aspx?Item=N82E16813130688] -
$109.99
CPU: Intel i5 3570k [http://www.newegg.com/Product/Product.aspx?Item=N82E16819116504] -
$219.99
RAM: G.Skill Ares 1600Mhz 2x4GB [http://www.newegg.com/Product/Product.aspx?Item=N82E16820231544] -
$64.99
GPU: Gigabyte HD7970 Ghz Edition [http://www.newegg.com/Product/Product.aspx?Item=N82E16814125439] -
$359.99
SSD: Samsung 840 120GB [http://www.newegg.com/Product/Product.aspx?Item=N82E16820147188] -
$99.99
HDD: WD Caviar Blue 1TB [http://www.newegg.com/Product/Product.aspx?Item=N82E16822236339] -
$69.99
PSU: Corsair CX600M [http://www.newegg.com/Product/Product.aspx?Item=N82E16817139048] -
$59.99
Heatsink: Phanteks PH-TC12DX [http://www.newegg.com/Product/Product.aspx?Item=N82E16835709019] -
$59.99
Case: Fractal Arc Midi [http://www.newegg.com/Product/Product.aspx?Item=N82E16811352031] -
$109.99
Optical: Asus DRW-24B1ST [http://www.newegg.com/Product/Product.aspx?Item=N82E16827135204] -
$19.99
Estimated Total Price - $1175
(They do get a lot more powerful than that mind you, just examples
)