Matt and Harry
OMG I love how they both had a little banter as Alec and Magnus in the ThosCon (is that the name of the activity?). Like this person asked them if Magnus would have his own show someday and Harry joked that he might look too old by then to act as a 20 years old. Then Harry and Matt started to talk like their characters having a conversation as old people! (I got the info from @shumdarionews, so go check their twitter ).
Ahhh I wish I was there, this is all so great! The cast is really amazing people honestly!