If I had to choose any post to show my level of english I would choose a writting about living without mobile phones.
Although it's not a long composition, the structure is very clear and there are lots of connectors and interesting ideas (in my point of view). It's also a common topic to talk about nowadays, so it shouldn't be boring to read!
Choosing an oral evidence is even more difficult. I choose the presentation of my TDR. I had been working on that project for so long that I think it's the best presentation that I have done, Seeing it again I can see how I wasn't that nervous. I was more secure and the presentation has a good structure and a lot of information.
All the posts helped me to improve my english, I think that the ones that I choose are a good example of my level. Nevertheless, I always see somethings that I could have done better!