If you have only one shovel in your garden tool shed, make it a long handled round point shovel. It digs holes, moves soil, lifts plants and serves as a level and hammer in a pinch.
The Ames® Kodiak® Round Point Shovel has an extended blade socket (where the handle slips into the shovel end) for greater strength. I has a nice lip on the back of the blade for bearing down on with your foot. The handle is 48" long, seal-coated premium northern ash. The choice of a long or short handle is personal, but if you're going to be digging holes, the long handle will save you a lot of bending. $22.30 - $27.35
You've probably guessed that this is the short handled version of Item #1. I'm partial to short handle tools because I think they have better balance and I can get a better grip.
This shovel also has a tempered steel blade with back lip and a strong northern ash handle. This time the handle is only 27" long and ends at a D-Handle grip. $53.04 - $62.99 from 3 Sellers
Gardeners with clay or rocky soil can easily wind up breaking tools instead of soil. The jagged sawthooth edge on this carbon steel blade does not take no for an answer. It looks more like a weapon than a gardening tool and you'll need it when you're trying to dig through tree roots and hardpan.
If you have difficult soil, you'll want a shovel that will last. Look for carbon steel blades heavy and the lip of the back of the blade is doubly important in tough spots. $39.99 - $53.49 Long and Short Handles
You'll be looking for the same qualities in a spade as in a garden shovel: strong blade, back lip and comfortable handle.
This one has a steel blade and color and a 48" fiberglass handle. Fiberglass makes tools lighter, but I haven't found them to be stronger than wood. If you're going to use your spade as an edger, go for the long handle. $20.99 - $30.99
For those of us who prefer short handles, there are, of course, short handle garden spades. The blade remains the same, steel color and flat, straight blade. The handle is still fiberglass, but it's only 30" long, ending with a poly D grip. $16.36 - $21.43
This isn't really a spade. It's a long, narrow shovel. You'll sometimes see them sold as landscaper drain spade shovels, just to make things more confusing.
Transplanting spades are useful little tools that do just what you'd imagine. They're for digging plants out of tight spots. The narrow blade (5-6" wide and 14-16" long) can slip between plants and get down deep enough to grab a good amount of roots, without disturbing the neighboring plants.
How often will you need something like this? Well, if you're a serious gardener, often. $25.67 - 51.38