Powerful and easy at the same time? Hmmmm.

Sid Loraine's slop shuffle, which can be done just as is or expanded ( taking out of the easy range ).

Double Back by Jon Allen - the most effective trick I do and fairly easy.

After much careful consideration, I'm absolutely certain that it is Daryl's Untouched (remember that one?). Seriously easy, incredibly powerful!
--Dan Harlan

Most powerful and easiest trick that I use regularly is Strange Voyage by Harry Lorayne.

Clutch by Oz Pearlman, since you can let the spectator shuffle the deck after picking a card.
I only skip the "card from pocket" part and retrieve the card in another way, this depends on whatever I can think of at that moment.

I don't think it was mentioned--there are a lot of pages here--but I like The Whispering Queen as a very strong card trick that is extremely easy to do. I use the version in Ron Wilson's book, the Uncanny Scot.

The spectator holds the deck, cuts the card while holding them under the table, places the cut card under her bottom, and returns the cards from beneath the table--all perfectly fair. The magician requests that the spectator hand him one of the queens. The magician explains that this is a "whispering queen" and that she is like a lot of ladies he knows: she cannot keep a secret. The magician notes that no one can know the name of the card except that the whispering queen knows it because she was there under the table, watching. Magician holds the queen to his ear and announces that she has whispered the name of the card and it is the Jack of Spades. The spectator checks the card under her bottom. It is the Jack of Spades [or other card].

Fogel's Triple Prediction.

Balducci Do As I Do by John Carey & Dr. Daley’s Last trick. Sometimes I do a quick Oil & water and finish with Dr. Daley’s last trick.

One more that packs a wallop: Sal Piacente's 4,5,6-Packet Trick

Chicago Opener, Minor Triumph and Double Finders.

But, for (Super) Easy and Powerful... Rising Signed Card, Signed Card to Envelope in Wallet and Signed Card on Ceiling.

For (Ridiculously) Easy and Powerful... Out of this World and Weight.

Beyond Fabulous - Dear Mr. Fantasy by John Bannon
easy mind blowing

Lazy Man's Card by Harry Lorayne
quick confuser

So many cool tricks listed. Awesome thread! Here's a few more:

1. Make My Day by Lewis Jones (killer diary effect).
2. World's Greatest Magician by Steve Beam (Semi-Automatic Card Tricks...volume 1 I think.)
3. Four Card Coincidence by John Murray and re-imagined recently by Mick Ayres in his book S'lie. (which is also full of many other high impact/low technical routines as all of Mick's books are.)

All three of these pack one heck of a whallop and there is not one sleight to be found amongst them.

Each of these effects can also be done with a borrowed shuffled deck in use.

DT3

+1 on Card Warp!

Let's not forget a very simple Card location using a (pencil marked) Key Card.

My six year old does it to the amazement of many Adults!

Wow, this is a great thread that everyone here in The Workers forum should read. As someone new to card magic, I have been able to develop an awesome top ten list of card tricks to learn.

The easiest card trick I know is probably "Harmony". Great effect .

Where can this be found?

Check this out: http://www.youtube.com/watch?v=mx7yJUlP340

An Impossible Conclusion by John Carey is an absolute gem of an effect that's both very easy and very stong

Easy isn't the first thing that comes mind after watching that...