Consider your own format only if you can articulate demands that are very unique to your scenario, and even then - (good) mesh formats are extensible and would probably suit your needs.
If you're developing in the MS universe there's DirectX's own .X format, which personally I think is very well designed. It supports animation, optional compression, and is highly flexible - you can define and register your own template and use whatever extra data you can't find in the presets.
Since it's fully open, there's even some work on using it without DirectX. It's main shortcoming is the somewhat lacking MSDN documentation - but that's more than compensated by online content similar to the links.
Beyond that there's obj and stl which are portable but rather primitive (stl in particular), 3dstudio's 3ds and really, tons more. What the world needs is not another mesh format..