If you have info to add, please do, as my memory is a little foggy on some of these and I never saw others in store at all.
Spyro's Adventure Sidekicks:
Included a mail-away card requiring payment of $2 and the UPC from the bag for your choice (based on availability) of one of four of the original sidekicks. Was limited to four per address. No coupons?
Spyro's Adventure Flocked Stump Smash:
Cards were inserted into bags with random one-time-use codes that you would use to enter into a website for a chance to win. There was a "free" entry method that required calling a toll-free number that allowed one entry a day and randomly selected winners. No coupons?
Spyro's Adventure Random Character:
Cards were inserted into bags with random one-time-use codes that you would use to enter into a website for a chance to win. There was a "free" entry method that required calling a toll-free number that allowed one entry a day and randomly selected winners. Pretty sure that all random figures awarded were Boomers and Wrecking Balls. This was back when Boomer was a major peg warmer, so it was a big joke at the time.

Spyro's Adventure $1 Off Coupons:
Bags had a coupon for $1 off a Skylanders Figure.
Giants Hot Head Giveaway:
Had "instant win" cards randomly inserted into bags. Could mail away for a chance to "instant win". Required winning cards to be mailed in. Winners were awarded a Hot Head. No coupons?
Giants Sidekicks:
Some packages included a card with a code, while others had the code printed on the inside of the bag. These codes were entered in an online site and required payment of $2.50 for your choice (based on availability) of one of four of the Giants sidekicks. Was limited to four per address. Contained coupons for $1 off any Skylanders character, $5 off a Giants starter pack or $10 or a SWAP Force Starter Pack.
SWAP Force Walmart Promo:
Included a coupon for $10 off the purchase of a SWAP Force starter pack and a free Walmart $5 gift card with the purchase of SWAP Force at a Walmart store.
SWAP Force "Exclusive" Fright Rider Promo:
Contained card with a one-time use code that would be used on a website where a random winner was selected once every 15 minutes. Winners will receive a specially decorated Fright Rider figure. Consumers could mail away a card to receive a free code via e-mail that they could redeem on the site. Winners were limited to four figures per physical address. No coupons.
SWAP Force Quick Draw Rattle Shake.
Had codes printed on the outside of the bags. Codes were originally one-time use, but due to the fact that codes were repeated across multiple bags, the contest was changed on the second day to allow the same code to be used multiple times. Entries on the website are limited to once per day per e-mail address and a random winner is selected every 15 minutes. Winners will receive an in-game variant figure of Rattle Shake. Consumers could mail away to receive a free code via e-mail, but this option was made redundant with the ability to reuse codes, even codes randomly posted on the internet. Winners were limited to four figures per physical address. No coupons.