Lord Shiva is distinct from other Gods primarily because he is always worshiped not as an idol but in an abstract form of a Lingam .
Secondarily, He is always worshiped along with Goddess Shakti (also known as Amba, Gowri, etc). In fact, in a Shiva Lingam the lower half resembling a yoni is the Mother Goddess (Amba ,Gowri).
Even when we do puja at home, we say Asmin Bimbe/Linge sumukham Samba Parameswaram Dhyami,avahayami and not Parameswaram dhyami avahayami..(Samba means Sa+amba Or with Amba).
While for all the other Gods its typically as given below:
Mahaganapatim Dhyami, Mahavishnum dhyami, Gowrim Dhyami, Adityam Dhyami(for Surya puja).
What are the reasons for this distinction?