It depends on what I'm looking for - accessories, or 'hard parts'.
I've gotten some great accessories deals on the Bay (just responded in another post about finding in-channel vent visors for $23 last year). I also remember a ACDelco fuel filter that came from there ('02-'04 use an external, along the frame rail.
For my stereo, I used Sonic Electronix for most of it. Have had really great service from them. Used to shop Crutchfield, but they're stupid expensive now (they mail me pretty catalogs, though). My f/r speakers, I bought retail, as I like to 'hear before I buy' on those. The loaded sub came from Sonic.
For hard parts, I'm often looking for a brand recommended on this site, or one that I trust myself. Rock Auto tends to be the easiest to find at the best price for that brand - even with shipping. The retail chains charge a fortune for the brands I want (if they even carry them), and they often have to be ordered (getting to me no quicker than Rock.) I've also gotten deals on clearance parts for my Voy from RA as well (I figured if they're on 'clearance', there's a good chance that scarcity may become an issue, and they were parts I could see needing to replace for various reasons.)
Once, I ordered from 1A Auto - I'd viewed so many of their YT vids that I kinda felt like I 'owed' them some business. So I ordered an actuator from them. They did have ACDelco, at least.
My Derale trans cooler & kit came from Summit; I think I also ordered some stainless trans pan bolts from them (bought them so that they'd not corrode like the OEM zinc bolts did, not because they were 'shiny')
I did get an alternator from Advance - it has a lifetime warranty, they're a national chain, my old one still has life in it, and it's about a 15min job to swap out on the 5.3 ...LOL Fluids & filters I'll get retail. My current engine oil, I actually get from the grocery (Meijer), as they often have a near-unbeatable price on the 5gal jug. Menards (like Home Despot, but regional) had a sale on the 1qt bottles, same brand - I stocked up.
I've gotten some parts from Craigslist, as well.
On a (somewhat) related point - I've gotten most of my trailer (camper) accessories from Amazon. Not all, but probably 90% of them over the last month.
Thankfully, after I bleed the last caliper in a few minutes, I'll be done with hard parts for a bit (ok, I might do the outer tie rod ends...but not soon). That reminds me - my new brake pads / rotors are from NAPA (on rec from
@Chickenhawk ). Will bed them in tonight, after traffic is off the road I'm using for that.
