I have the Maxis 235 75R15, whitewall. Love them. Smooth, silent, balanced and interestingly, they won't go square if the car sits for a month. But the real plus is the 75 in the number, providing you more curb clearance (for the US readers: we don't have those rounded-style curbs here, but edgy wheel-killers instead).
The higher aspect ratio may give this tyre more ''buoyancy'' too, resulting in the smooth ride.
I heard that Hankook makes 75s whitewall too, and that those have a good reputation as well.
On the US RROC, someone sells 5 new Hankooks for a bit over 300USD, fyi.