The big bounce, and of course a multiverse itself, to name two that are currently conceivable.
Not quite.
Oscillatory models of the universe prove to be far less likely as the "Heat Death" models. It is impossible to extend space-time through a singularity to a prior state. Even if the far-fetched oscillating universe theory is true, the question remains: what caused space-time and energy to come into existence to be able to observe such a phenomenon as the oscillating universe theory?
The same applies for the Multiverse; sure, it manages to produce a means to how our universe came into existence, but how did the Multiverse come into existence?
As I said, the absolute beginning of the Universe, or existence, is unavoidable.