And do you need a new gasket for the oil filter cover every time?  How about a new crush washer for the drain plug every time?

I get my oil and filter at A$$vanced auto.I use Fram filter and Valvoline motorcycle specific oil.Cost bout $11.My drain plug has an o ring.I just clean it put fresh oil on it and reinstall.No leaks so far.Fram filters have the gasket/o ring for the filter cover included.I reuse mine.So far no leaks there either.

I buy oil filters at my local dealer. They are only about $6 a piece, so I don't bother shopping around.

Same philosophy goes for the oil filter cover o-ring and crush washer: they are so cheap that I replace them every time.

http://www.amazon.com/gp/product/B000ICRIVY

according to this website purolators are much better than some other brands.
http://www.calsci.com/motorcycleinfo/Consumables.html#OilFilters  i bought em cause they're cheap and got free shipping.

Hi there,
I have always used the OEM Suzuki filters and always replace the o-ring and drain plug crush washer every time.
Never had I had a problem or a leak, except when I once forgot to put the new oil filter o-ring into the groove... but I digress...
I've been riding and maintaining my own motorcycles for 33 years and highly recommend staying with the OEM oil filter and always replacing every o-ring, cotter pin and crush washer every time you remove them. They're cheap and keep you from having problems on the road.
Best wishes,
Todd

I get them at the local dealer that orders them trought parts canada,
I get the k&N one, since it's cheaper than the suzuki one. about 7-8$cnd each. come with a o-ring too.
change the o-ring every 2 oil change, and never changed the crush washer.

I change the oil after storage, twice during the season, and once before storage too! I live in canada

bike has 14000 kms... no leaks