It mostly depends on how many other people are mining the same coin at the same time.
CPU mining was massively profitable last year for BBQcoin for example when no-one was bothering to use GPUs to mine it, a whole bunch of people all put just one CPU core onto it for about a year, then sold for fortunes when it came back into the public eye.
Basically you need to look for coins that are pretty much abandoned, and just direct the least amount of hashing at them that will get you some blocks, and just sit that out hoping it is a long long time before the masses regain interest in that coin.
Otherwise you pretty much have to go with super hardware and low electricity prices no matter what you are mining, including things like primecoin and protoshares and such.
-MarkM-
Electricity is always the killer when mining. Lucky it winter now, it mostly off peak prices until spring. XPM and PTS are more profitable in my situation at the moment. BTC seems to drive down GPU mining at the moment because of it's surge is price.
For me, this past week, I have to agree with you on CPU mining. I think I have made more than I have in 3 months of mining with a HD7970, thanks too a bit of PTS luck lol.
XPM been a consistent payout, but PTS has potential to be explosive once the genesis blocks start and Bitshares comes online. I just have 100 PTS at the moment, which I got on day one mining 2 blocks. I'm pool mining at the moment at Beeeeer's PTS pool. My GPU's are at idle for most part of the 3 weeks now. I've been investing in securities to at cyrptostocks.com .
