Your Current Specs: none, it's a completely new PC in addition to my main PC
Budget: 500-600$
Main Use: strictly co-op and multiplayer gaming
Monitor Resolution: 1920*1080. Will upgrade in 2-3 years. I'll have to buy another monitor.
List SPECIFIC games that you MUST be able to play: drops to 30 fps are acceptable, people will play multiplayer shooters and action games. High settings, but not ultra or maxed out.
Looking to reuse any parts?: I have a tower case from one of my old PCs, keyboard and mouse.
When will you build?: next weekend
Will you be overclocking?: No
With that budget, go for the Standard build. I can vouch for it as that's what I built and so far it has been rock solid.