It's easily to download chem- draw 8.0 or altra for free online then setup to use. another way ;u can register in MedChem Designer then Download the software program. then easily setup to work on it.please use this link :http://www.simulations-plus.com/Products.
Chem3D (from CambridgeSoft ChemOffice-you can export planar structures from ChemDraw).
Hyperchem, ChemBioDraw, VegaZZ.
The graphical interface of Gaussian (GaussView). With Hyperchem (or GausView+Gaussian which is more advanced) you can make also different calculations (geometrical optimization, dipole moments, and other complex calculations).
For reactions schemes ACD ChemSketch is free and very good (IsisDraw is also OK but for some publishers it is not used anymore), Symix Draw (I think is also free). Mercury for visualization of the cif files from the X-rays.
Just for drawings of 3D structures (For a presentation for example) I personally use Hyperchem.
I would agree with Chem3D. I use ChemDraw for most simple molecules and Chem3D for anything more complex, while still being relatively low cost. I guess it might be more helpful to know what you are interested in drawing to give a more complete answer.
I find ChemDoodle to be useful, especially for drawing organic molecules or designing figures. It works on Windows/Mac/Linux systems and also has a mobile version. There is a license fee, but you can start off with the free trial version to give it a spin.
Chem draw, ISIS and chem sketch are easy and appropriate to use.. among them best is chem draw because maximum journals ask you to draw structures in this software...