Well firstly stay away from Gold.....it had an awful year in 2013 and is set to not get much better into 2014.
Oil isnt much better nor is silver...both of which are on a decline.
A very risky and volatile, but possible high return in Bitcoin....allthough this can be risky if you arent certain on what you are doing and backing up your wallet etc.
The safest and steady growing investment is property....but its not quick to get in or out of....so for 12 moths that isnt suitable.
Stocks are a good investment if you know what you are doing.....companies like Westminster Group PLC (WSG.L) had a fantastic 2013 and looking to replicate into 2014....but like anything its a gamble, unless you keep your eye on this everyday.
Remember the inflation target for this year is 2%......so as long as your are getting better than this in an ISA then you will actually be worse off come the end of the year.