No multiplayer games don't require heavy duty bandwidth - most run just fine on 256kbps unless you're hosting the game - that's the only time when you'll hit issues.
Windows services use relatively minimal upload traffic, they may hit the download hard very occasionally but if you're a ton of them soaking up bandwidth having more upload just means these services (backup services or something?) have more bandwidth to use.
When there are 50 people on the map and you need to download the, say if using 30 fps resolution, 1500 position updates per second from the server worst case, why would you be using upload?
Games apart from World of Warcraft that I'm aware of use a protocol called UDP - there is no need or desire to upload anything when you're downloading other people's movements, you only upload your own movements. That's really not a great deal of data per second.
I don't need to say how expensive or otherwise our broadband is, Ookla's stats put us 5th cheapest.
http://www.netindex.com/value/
If you saw huge differences on a 50Mb/10Mb line it's because as I said before your 30Mb isn't working properly. Pings shouldn't get shot at peak times, either you've some issues or someone else in the house is running something that's chewing the bandwidth - it won't be baseline Windows services their usage is extremely minimal.