If you have VERY low electric cost (3cent/KWH ballpark), you can mine and have a good chance to achieve RoI on the S7 (and the upcomming Avalon 6) under recent conditions. It appears that the upcomming Lketc/BW.com unit might be even better (mostly due to lower projected cost), but the pricing on that one is still uncertain and availability is still up in the air.
If you build it right and have fairly low electric cost (under 7c/KWH, perhaps a little higher), you can mine DASH profitably with a GPU rig (but the RoI will take well over a year even with 3cent electric, assuming recent conditions of DASH don't change).
I've not done a calc on Litecoin lately, other than on my existing Gridseed Blades (which are a hair under break-even currently with 6.7cent electric, gonna be shutting them down once I hit my next payout from my pool). Anything noticeably more efficient like the Alcheminer (and clones), the A2 based miners, and especially Titans should be profitable at 10cent electric but RoI might be problematic if you don't already have the gear.
Chances of ROIing on a GPU rig are pretty slim I think anymore. The coins are just not worth enough to make a profit over electriciity where a substantial amount is there to pay off card's. You might find a coin now and then to profit from but I don't see ROI happening.
The hope I have is Lketc/BW is cheap like it should be. Not sure if this will happen or not, but it would be nice if they did. Part of reason is bitmain has a track record of lowering to try to beat competition.... so good for miners.