What, in your opinion, is the best effect for under $30?

Are you referring specifically to marketed (singular) effects, or are you interested in books and other resources?

If you want bang for your buck then ICandy is extremely good as it teaches a lot of effects and is only $22. My favourite effect is Panic by Aaron Fisher.

Hi,
I like Panic as well, at least the entertainment aspect, because I have not performed this trick. The question was intended for tricks/gimmicks, not books or videos. In other words, what would be the best trick to buy for under $30 that would really impress people close-up and on the street?

That is a really hard question to answer. Have you just started? What are your likes? Cards, coins, mindreading, or general close-up? I have done great with panic. You may want to get that one out from behind the mirror and try it out. Assuming you have given it the practice that it is due I think you will be pretty happy with it.

There is no BEST effect but there are GREAT effects and FAVORITES.

Sponge Balls
Invisible Deck
The various Three Card Monte effects available
Invisible Card Punch by Dave Powell
Slyder by Jay Sankey


New effects:

meLt by fellow Penguin, Eostresh
viewtopic.php?f=2&t=161388

The Vanishing
http://www.hocus-pocus.com/magicshop/?p=20172

I agree with EZrhythm and eostresh, which is why I wanted to clarify what it is that you are looking for.
There is no proper answer, because one performer can make an effect fall flat while another can perform the same feat and garner one thousand times the reaction.
Great reactions accompany great performances. Take Pop Haydn as an example. Where skill is concerned, he does nothing outside of the realm of the amateur. However, his performances are wildly successful and memorable because he has the shrewdness and showmanship to take simple tricks and mold them into entertainment while still maintaining the wonder of the inherent magic.
The moral of the story is that you cannot rely on an effect for reactions. You must rely only on your own creativity and passion. If you are inspired to connect with the audience, you will make a great performance out of anything you do. So buy the effect that most inspires you.

On another note entirely, if you are searching for a trick that is under $30 and is still very well esteemed among the audience if the performer isn't paying any attention to presentation, then here are some recommendations:
~ Invisible Deck
~ Scotch and Soda
~ The Raven
~ Svengali Deck
~ Professor's Nightmare
~ Making something vanish
~ Making something appear
~ Making something transform

Most importantly, though, remember this: The audience will be far more likely to respond with guesses as to the method than with astonishment and praise if they don't appreciate your presentation. Without showmanship, you won't be able to develop rapport with the audience, and the reaction to ANY trick, no matter how baffling, won't be as great as you hope. Given the same amount of astonishment, an audience watching a boring magician will respond with half as much zeal as another audience watching a charismatic, amicable, personable magician.

My favorite sub-$30 effect is "In a Flash" by Jay Sankey. A few years ago everybody was doing it, but it's a lot less common now.

You might also think about investing in a DVD instead of a specific trick, as most have as many as a dozen tricks on one DVD, sometimes more. My favorites are "Front Row Sankey" and anything by Richard Osterlind. If you are into mentalism, you definitley need to invest in an Osterlind DVD, I recommend starting with the first Mind Mysteries Volume.

Invisible Deck
Svengali Deck
Sponge Balls

And your favorite magic using a normal card.

Duh...

There have been a number of great suggestions but I would definitely check out Trilogy by Johnny Ace Palmer DVD and Johnny Thompson Commercial Classics DVD. Some of the best DVDs on close-up and if you master the material you would certainly be able to amaze. If stage or parlor is your thing I would consider on of the Martin Lewis Making Magic DVD's, he will teach you a whole fantastic routine you can make and lastly if mentalisim is your thing I would try one of the Osterlind DVDs.

As I'm a big fans of card tricks, this has been a real great journey into card tricks: http://www.penguinmagic.com/p/S14576

*Cough* modern triumph *cough* lol I like Panic as well and have been playing with Key Deposit from Sankey.

It APPEARS that FAX by Loki Kross is in the que to become a "best effect" category winner.
http://www.penguinmagic.com/p/2916

I'm definitely waiting for some reviews on this before purchase.