It's really hard to justify getting more than a few figures in the DC Universe Classics line due to Mattel's insistence on reusing body sculpts as much as possible. Once you get one of each of the basic boy types (average male, large torso male, female, teen male, guy in suit), anything beyond that is pretty redundant unless there's a large amount of new tooling or parts.
When the line started, I knew I definitely wanted to pick up core Justice League members, as well as certain other characters that I liked (like some villains or Justice Society members). Sure enough, I got Green Lantern, but having that figure made my later acquisitions of Orion and Blue Beetle (which are essentially the same figures with new heads and different accessories) feel a bit redundant. Not to mention the thighs are used on even more figures I own, including Captain Marvel, Green Arrow, and Hawkman. All this reuse has really turned me off from picking up other characters I would otherwise be open to acquiring figures of, including the Spectre, Mr. Terrific, and Wildcat. It's even more disappointing when comparing these figures to my Marvel Legends collection, which (excessive reuse of the Bulleye body aside) primarily relied on original sculpts for each figure. So after my brother got me the (new to me) Question and (all brand new) Deadman figures, I've pretty much vowed to myself to only pick up unique or heavily retooled DCUC figures.
How many wholly unique figures have there been in DC Universe Classics? Well, here's a rundown, based on the best of my knowledge:
Gorilla Grodd (Collect-n-Connect)*
Solomon Grundy (Collect-n-Connect)
Blue Beetle (Jaime Reyes)
And for those interested, figures that have enough new parts or tooling to not look like other figures already in your collection:
Mantis (Super Powers variant)
*From preview images, it's likely Ultra-Humanite reuses the arms from Gorilla Grodd.
**I've read one review mention that Desaad reuses parts from Sinestro, but I can't verify that. Even then, it would be just the torso, crotch and thighs, as everything else is new and the figure's body is covered in a cloak piece.
***This mold was originally released as a white-coloredSan Diego Comic-Con exclusive, but this version is the one originally intended for release. Even then, only Man-Bat uses this body.
****The forearms and thighs might be reuses.
*****The legs and arms might be reuses from Black Canary.