I have quite a few Funimation releases I'm holding on until the Blu release comes out because you always know they will release them. Panty & Stocking I like but again, like Dark_Sage said, I'm waiting for it go cheaper before I bite on it (seen it all, just not buying it yet). But then we have animes like Deadman Wonderland and the first season of A Certain Magical Index that are currently DVD only... until the inevitable re-release hits and it comes out on Blu.
After I got all of Soul Eater on DVD in 2010, it hit Blu only a few months later. After that, I never bought a new Funi anime unless I knew it was something that was not in HD (which is extremely rare these days).