Games are probably the most intensive applications a normal user will run on a computer. Any computer that plays games well will by default do just about anything else well. Specialized computers for things like 3D rendering, or audio work may not be great for gaming, but will usually be just as good for normal desktop type stuff.
So yeah, get a "great gaming computer" and you've got a good computer.
What Dell et al considers a "great gaming computer" and what power users consider so are probably different however.