Samsung Wave is fantastic device, if you're comparing it, or planning featurephone usage out of it. The screen is extremely sharp, because you're packing WVGA into a 3.3" screen. The body feel is tight, solid and its metal, so great classy build. Wish Samsung makes an Android out of it too, as Bada seems like Android lite. Cant say much of the rest since I only handled and tested it, but not in daily usage.
For the price you're paying it, you might as well go for the Galaxy S, however. No matter what, in the end, it will boil down to an Android vs. Bada comparison, apps vs. apps. Plus the fact that no matter how sharp the screen is on the Wave, a bigger screen like the 4" on the Galaxy S still rules.