Rank the following radicals in order of decreasing stability
Here, 1 and 3 are aromatic since they follow Huckels rule(Or am I wrong here?   


Yes you're wrong over here, for applying the Huckel's rule the compound must be a closed circuit of delocalized electrons. In both the cases the circuits are not closed   



If you're not aware of Conjugation then give that a read .
Now 
The most stable compound is 3 since the extent of conjugation is the greatest i.e 2 pi bonds.  

3 is more stable than 4. Even though 4 is aromatic it is an aryl free radical the p orbital containing the radical is out of the plane and can't be stabilized through resonance/Hyperconjugation.
In fact I would say that option 4 is the least stable compound .   

The second most stable compound is is 2 since it is stabilized via resonance which is more effective than Hyperconjugation; 1 is stabilized by Hyperconjugation.   

3 is more stable than 2 since the extent of conjugation is greater.

The order of stability will be
$$\mathrm{3 &gt; 2 &gt; 1 &gt; 4}$$