Too many factors to give an answer on this one.
If you had a good connection, and were, say, playing League of Legends from Australia on the North American server, you might be connecting to a server in Canada, and distance from the server would be the primary factor. There'd be little you could do to drop below 200, just off that factor alone.
Wireless vs Hardwired is another one. Wireless will add 50-70 to your ping sometimes, depending on your router.
Other network devices don't help. For example, if you had a DSL Modem connected to a router, connected to a switch... it'd obviously add some ping. Connecting directly to the modem would be faster, if that was doable.
Firewalls. Maybe you have an Antivirus with a software firewall, and the Windows firewall is also running, and your router has a firewall. They'd all potentially contribute to higher ping.
Router settings are another factor. Does your router let you prioritize certain traffic? Maybe tweaking the settings will help. Also, maybe you can add a firewall exception so the router's firewall doesn't slow you down as much.
Or... maybe your ISP is just terrible.
Or your computer just sucks (slower computers will have higher ping, just due to higher CPU utilization, and other bottlenecks).