My budget restricts me a lot! It used to be Copper Glow: I'd always miss out on her or just not quite make it through. I finally, finally have her.. She 'aint leaving (unless I end up with hilarious hospital funzies again).
At the moment it'd probably be the Merry Go Round Sparkler/Diamond Dreams: I can never chase them high enough. And I try to get the full Sweet Celebrations family when I see them to pair with the Little Sister that I've had since I was three, not sure I've ever had them all at once.