Each promotion has its little nuances to them. For example the turkey15 really only work out if you could get the 15% to pay for your shipping. This usually meant spending about $150 to offset the shipping. The Freeship75 was great if you could also take advantage of sales (like Souvran) plus you got the $10 coupon and 12 days of xmas (This was a great deal, because you could get everything tax free as if you were in the store). This sale with 20% looks best also if you can keep shipping low. I got some cheaper items this morning that were on sale, so after everything was said and done I ended up paying $1.00 for shipping. It is pretty much all a numbers game.
Also with Autogeek, be sure to check their other sister sites. Sometimes they run specials in parallel with Autogeek, but be careful there sometime little differences. Like with Soveran Autogeek sold: buy one get one with $10.00 coupon and free shipping. Pinnacle sold it BOGO 69.95 with just free shipping. It was pretty much a similar deal.