mostly cuz of ur hacks
but anyone can and should do these things to reduce lag:
close background programs, such as chat managers (AIM, MSN, Xfire), even stop programs running under task manager, streaming music and/or videos lags, downloading/uploading things will also lag you, runing virus tests lag you, turn off torrents/bittorents (such as limewire, azureus)
you dont need a router unless you have more than 1 computer running through it, and running more than 1 computer through it risks limiting your available bandwith or slowing down your connection if your waiting on router packet control. if your on a decent router and no one else is using a computer, it really shouldnt matter if you connect through it or not, its only a 1 or 2 latency (ping) increase unless its stopping your data to send data through for another computer