I would like to suggest the following paper:

Lape R, Colquhoun D, Sivilotti LG. On the nature of partial agonism in the nicotinic receptor superfamily. Nature 2008;Jul 16. [Epub ahead of print]:1-7

What I like about this paper? Even though this is not my area of expertise, I can understand the paper without great difficulties thanks to the plain language used. An example is the introduction that starts with the following sentences:

Agonists are small molecules that bind to a receptor and activate it. The best understood receptors are ligand-gated ion channels.

The paper also has a clear structure and the logic can easily be followed. It helps that the model propoed in the paper is straighforward and that the experimental data support the conclusions without great difficulties.