Are there any alt coins that would be viable to mine with CPU ?
If you dont have free electricity it woun't be profitable to mine with the CPU.
A resonably modern AMD GPU can still make profits mining altcoins thou, a 5850 for example, underclocked and undervolted is still profitable on the second biggest coin LTC and even more so on other smaller coins, you can compare profitabillity at http://www.coinwarz.com/
an 5850 at 282Mhz/s, 92 watt and relatively high cost per kw/h in this example:http://www.coinwarz.com/cryptocurrency/?sha256HashRate=282.00&sha256Power=92.00&sha256PowerCost=0.1800&scryptHashRate=282.00&scryptPower=92.00&scryptPowerCost=0.1800
Fastcoin (FST) seems to be the most profitable today, generating 3 times as much USD as if one would mine btc instead, but that changes from day to day so have a look there.