In your opinion, are cosmological arguments or teleological arguments better at proving the existence of God?

Cosmological and teleological arguments are theological attempts to prove the existence of a god using the tools of logic in the absence of observable evidence. 
Cosmological arguments posit that a natural Universe driven by cause and effect cannot have an infinite history but that a god can, and therefore proponents assert that the Universe must have been created by a god. However, this argument can be objected to on the basis that it "begs the question" (argues the assumption), this is a situation where an arguer assumes the very fact he or she is attempting to prove. Here, the argument assumes that history must be infinite and that the only possible thing that could have an infinite history is a god. The tools of logic are only useful for showing whether a particular assumption leads to a particular conclusion, and so circular arguments proving their own assumptions are always invalid, and this therefore leads us to question the worth of the cosmological argument.
On the other hand, teleological arguments attempt to demonstrate the existence of a god by pointing out aspects of nature that appear designed. While this seems to be based on observable evidence, the premise that something in nature must be designed is still an assumption. It is therefore, once again, a case of begging the question. A quick look through history reveals an almost limitless number of assumed designs that we now know to have purely natural causes: lightning, earthquakes, floods, volcanos, the motion of celestial objects, weather, comets, geographical features, illness, and so many more.
Therefore I propose that teleological arguments provide the best argument in favour of proving god's existence as it firstly does not suffer the downfall of begging the question as cosmological arguments do, and secondly it is supported by the world itself that we see.