depending on the speed of your dsl or cable depends if they would be any good. if you only have 300/100 (d/u) then your ping wouldn't be all that great, if you got a meg connection with around 300+ upload then you got a decent online game playing connection. Of cource a T1, DS3, or an OC-XX connection would be wonderful but not fiesable for most (including yours truly) the best connection that most can afford to get into is a LAN game.
The fastest connection I can afford (Cable right now ) is the best connection. My connection is usually 50-80ms on most servers for porn downlo...oh, um gaming.