Yeah, yeah. OP munchkinry, wrongbadfun, broken, etc. etc. Let's just skip all that, can we, and just discuss what patron is the best for the Pact Wizard?
My opinion is the Endurance patron, as it gives access to a number of great defensive spells that are great to spontaneously cast, most of which are unavailible for Wizards normally (and, of course, gets Miracle). What else is a powerful option?
Healing, on the basis that it fills the biggest hole in the wizard's spell list, or Peace for a bunch of defensive spells it'd be nice to have on hand all the time, or Shadow for eventually just about every conjuration or evocation spell on tap all the time ... At higher levels I might go with Shadow, but starting at level 1 Peace seems useful faster.
And yes, that is one OP archetype.
Ooh, having all the shadow spells on hand would be really nice. Portents would be handy at low levels, allowing you to toss around ill omens with the best of them, but it fades off pretty quickly, giving you little else of note besides divination. At mid to high levels, I might actually go with Time. It only gives you one spell from outside the wizard list, but that spell is threefold aspect, which is a fantastic boost for a wizard to have, especially if you're in a low-wealth game or otherwise don't have access to a good headband. Just as important, though, it gives you a bunch of spells that would be wonderful to have on hand for spontaneous casting. It's hard to overstate the value of always being able to cast a crucial silence or haste, a teleport or disintegrate.