I have two options that I find the best.
Rock Auto as noted above.
Local option in Edmonton, Parts King. Great pricing and you can pickup. I found they are very close to Rock Auto after shipping on most stuff and they usually have it in stock. You can email and they get back to you right away. If you request that they call your cell number they will and they will work with you to find what you need. Great service. They may not have everything but I found they have been good for me.
www.partsking.ca