This is my complete Skylanders collection (I don't have the sidekicks, because they don't actually count, nor do I have any of the variant figures, which also don't count), and includes the following:
All Core figures (the normal, default figures), all 8 Giants (just big figures, one for each element), and finally all 16 SWAP Force figures (the figures with magnetic, swappable halves; Doom Stone isn't pictured because I ordered him off Amazon):
Magic: Spyro, Dune Bug, Hoot Loop (SWAP), Trap Shadow (SWAP), Pop Fizz, Wrecking Ball (found by accident), Voodood, Star Strike, Double Trouble, Ninjini (Giant; favorite Giant), Deja Vu
Life: Camo, Stealth Elf, Zook, Bumble Blast, Tree Rex (Giant), Grilla Drilla (SWAP), Stump Smash, Shroom Boom, Zoo Lou, Stink Bomb (SWAP), Food Fight, Bush Whack (Trap Master)
Fire: Flameslinger, Sunburn, Eruptor, Hot Head (Giant; I can't be the only one who thinks that Hot Head and Eruptor should've switched names), Fire Kraken (SWAP), Blast Zone (SWAP), Fryno, Hot Dog (cute), Smolderdash (VERY hard to find non-Lightcore), Ignitor (probably better as Igknightor, but what do I know?), Wildfire (Trap Master),
Earth: Terrafin, Crusher (Giant; subtle name), Bash, Flashwing, Rubble Rouser (SWAP), Doom Stone (SWAP), Dinorang (won on eBay), Prism Break, Scorp, Slobber Tooth, Wallop (Trap Master), Fist Bump
Undead: Cynder, Ghost Roaster (impossible to find btw), Hex, Chop Chop, Rattle Shake (SWAP), Fright Rider, Roller Brawl, Grim Creeper (Very hard to find non-Lightcore), Eye Brawl (Giant), Night Shift (SWAP), Krypt King (Trap Master), Funny Bone
Water: Gill Grunt, Slam Bam, Wham-Shell, Chill, Riptide, Zap, Punk Shock, Thumpback (Giant), Wash Buckler (SWAP), Freeze Blade (SWAP), Snap Shot (Trap Master)
Air: Sonic Boom, Whirlwind, Swarm (Giant), Free Ranger (SWAP), Boom Jet (SWAP), Jet-Vac, Scratch, Pop Thorn, Warnado, Lighting Rod, Gusto (Trap Master)
Tech: Sprocket, Drill Sargent, Trigger Happy, Spy Rise (SWAP), Magna Charge (SWAP), Boomer (also impossible), Bouncer (Giant), Drobot, Wind-up, Countdown, Gearshift (Trap Master)
I also have the pieces for Pirate Bay, Sheep Wreck Island, Tower of Time, Empire of Ice, Mirror of Mystery, Darklight Crypt, and Dragon's Den, as well as the items associated with them. I apologize for the amateur photo, but I tried to get all of them in the shot.
UPDATE: Doom Stone just arrived, so now I truly have a complete collection.
Udate 2: The bad news- of October 7th, 2014, I longer have a complete collection; the good news- I'll be posting an updated picture for both this and my Disney Infinity collection once I complete that. Whichever one I end up finishing first is the one I'll update. This is going to be a very stressful holiday season for me.
Update 3: Seeing as how my collection has gotten too big for one picture, I'll be posting four separate collections (possibly six, counting the Traps for Trap Team and the Sidekicks since they actually count in this game and are full characters instead of accessories); I'm also updating the roster of who I now have.