If a spell is countered, will triggered abilities that trigger when a spell is cast go off? Ex: If i have {Sigil of the Empty Throne} will i get the angel even if my enchantment spell is countered?
yup. a spell being cast and a spell resolving are two different things. countering a spell will prevent it from resolving, but it wont uncast it. youll get an angel and {guttersnipe} will still {shock} players if an instant or sorcery is countered.
Added ruling; definition of casting. Older card mention successfully casting, which is obsolete.
601.2. (http://imtgapp.com/forum/index.php?action=imtg;area=rule;number=601.2.): To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. Casting a spell follows the steps listed below, in order. If, at any point during the casting of a spell, a player is unable to comply with any of the steps listed below, the casting of the spell is illegal; the game returns to the moment before that spell started to be cast (see rule 717, "Handling Illegal Actions"). Announcements and payments can't be altered after they've been made.