mosnab, I don't collect this line but do look at them in the stores. The only fig I never saw on the shelves (not counting new waves such as Whiplash, Two Bad and later) is Merman. Every other fig was readily available, including Beastman and Stratos, whom from what I've gathered were somewhat hard to find.
You're probably going to have to resort to ebay if your interested in any of the older figs, as they have pretty much dried up. Most likely the latest wave available in the stores would be Prince Adam and Sy-clone, with Whiplash, Two Badd, Man-E-Faces and Buzz-off showing up shortly (if not out already). Walmart does have some of the older figs (TrapJaw, Orko, Teela, Triklops) availabe with a video. I believe the figs are the same exact ones as their single card counterparts, so it might be worth a look.