I am having one hell of a time finding a finale for my show. I mean, there is a lot of good stuff out there. But nothing that is exactly a finale. I was wanting to are your finales? I am not stealing your stuff, just food for though.
Frist things first.... what kind of show/act are you doing?
I didn't notice anyone asking you this question and it needs to be known first in order to give you an educated and appropriate answer.
As an Illusionist (think Copperfield, not this new lame idea as to what that means) I'd close the show with one of my best routines and even that depended on which show I was doing; the Macabre show ended with the Buzz Saw while my family show typically ended with either a circus or patriotic mode (the latter is always garunteed to give you a standing ovation, just ask Elvis).
The traditional magician, someone like Norm Nielson who'd just completed an uncanny manipulation act, would likewise have multiple endings based on what the client wanted. His full act ended with his floating Grand Piano but more typically he ended with his version of the Coin Ladder & Miser's dream. . . his previously vanished floathing violin, sneaking out from the curtains to take a bow in encore.
My point being that theme and the type of magic you do means everything! That is,
IF you don't want to be another clone -- another guy doing the same exact stuff everyone else is doing.
An "Act", "Show", etc. isn't a bunch of tricks tossed together, if this is how you are approaching things, please get out of magic NOW!
Learn about showmanship and then script writing (getting some storytelling under your belt wont hurt when it comes to the latter). Then decide on your character and what is appropriate to him/her. . . not what you want to do but what is APPROPRIATE to that invented entity and the type of audience you plan on focusing on... and be realistic, you aren't going to be on the Vegas strip over night unless you have at least a million to burn on room rent and ads (it's called 4-walling, which is how most major acts actually work -- far more profitable than being hired but not for the lazy or poor).
If you are just starting out 90% of the gigs you do will be very low pay and if you're shooting for the club gigs, you'll be on a very small, shared stage (nothing like having a drum kit bumping your butt while doing Professor's Nightmare). You need to consider this before you get started. You need to think about lighting, what you will have avalable and if there's a curtain that can open or not (due to critter loads or even people loads).
All of these things MUST be wieghed before you worry about a finale. . . because this forum has a word count issue I'm going to continue this lecture below. . .