Whether you want to draft with friends or open packs just to see what you get, Play Boosters are specially balanced for play and fun to open, with 1-2 foil cards and 1-4 cards of rarity Rare or higher in each pack, plus the possibility of an Art card showcasing a piece of art from the set
Colorless spells on the other hand can be played in any deck, so if there were too many great colorless instants, those cards would start being played in pretty much every deck
With the launch of Pokemon X and Y, the games introduced Mega Evolutions
Whats worth knowing: Foils often feel different (sometimes thicker, sometimes curlier, sometimes both)
Wulfgar of Icewind Dale plays well with lots of the other cards on this list that have attack triggers, like how Savage Ventmaw gives you 6 mana