Since it has so many posts in here, I think this is a good way to put up impromtu tricks. I know that it is more than five, but I would like to share. (Not in order)
Sloppy Shuffle Triumph
Commerical Aces (Syd Segal)
Collectors Editions (Syd Segal)
The Omen (Aaron Fisher, Paper Engine)
Logical Lesson (Syd Segal)
Do As I Do (Royal Road to Card Magic)
Search and Destroy (Aaron Fisher)
Double Shock (inspired by Paul Harris with reset, Lu Chen and Yuichi Katakura)
Criterion (Chad Nelson)
2 Card Monte (David Blaine)
Five Speed (I know it's gimmick, but a small setup)
Role Play (D+M)
ACR (ending with card to mouth or Pixel by Jade David)
Four Card Revelation
Hmm.. This is hard but the ones i perform often that are impromptu are..
Subway by Dan&Dave From Five the notes
Meld by Dan&Dave From Five the notes - As simple as a DL but the patter is amazing
3 Phase or 7 Phase Ambitious Card Depending on audience etc.
SEARCH & DESTROY by Aaron Fisher - its brilliant
Just a tip to everyone out there. I'm not saying to ditch the knucklebusting tricks because trust me those are fun and i like em. But im just saying that theres ALOT of simple tricks that hit hard. Just try to switch of your repetoire once in awhile.
Only starting but use it these five everything i perform
Own sandwhich routine(Just a card put back then i display the cards, spectator shuffles the deck. Then pick four cards they touch three cards. Then use Kings or Ace to find there card. the Two cards sandwhich the thier card.)
Kick @$$ card trick.
5 is the best i lve her? i need to no what my mom say to me...
the tiles mean some thing but you got to work out who mom had a son with a name ew but we all no his new name what is it ?
unbelievable by michael shields &bascom jones junr
color i- do-as u by george boston
and the 12 card tricks the is in eddie joseph book / eddie's dumbfounders with cards no skill- no sleights- no moves. and the protean card magic by a old but new paul gordon..
we see things but can not be seen but we by the old that is new to use all when we put the mad man to show world and act that is so new to see... did you know the five on a dice is called cinque .. by for now jr? allwood
I find it quite hard to find and name just 5 of the impromptu card effects I do, but I'll give it a try:
I.T.C. aka Invisible Telekenetic Card - A very simple yet hard hitting card effect that I created. I also use it for my opener whenever I perform, and the selected card can be signed or even use a borrowed deck.
Ambitious Card Routine - A true classic and has never failed me once, and the audience loves to participate during some of the reveals.
Card to Various Locations - Another favorite of mine, is to have the spectators signed card disappear and then appear in almost impossible conditions. Signed card to pocket, wallet or even the signed card in sock routine.
Two Card Monte - Another favorite of mine which most spectators think they can win, even though I suggest an imaginary bet. There's another version of Two Card Monte which is taught in Mark Wilson's Complete Course of Magic. Now although that particular variation looks really good, but it's not 100% impromptu.
Magic w/ Aces - There are just too many card effects that utilize the 4 aces, but they're also one of the more fun effects I like to do with four cards instead of the whole deck.
Triumph (Royal Road version)
A/C (different each time I do it)
Twins (brother Jon Hammond) -spelling?
Two Card Monte
Mind reading Force
some other ones worth mentioning...
I have been doing .44 (Daniel Garcia) a lot lately.
I always carry my own cards in my back pocket and i almost always have here then there and Chicago opener ready, I know that's not exactly impromptu, but it looks that way when i pull the deck out.
Literally anything that doesn't involve a gimmick. You could set up for an ace cutting routine in front of people and they wouldn't be the wiser if you have a good Cull. Hell you could use that to set up for LITERALLY anything if you're good at it.