One East End neighborhood that really shines, in my opinion, is The Beach. I think part of the reason is that it offers and excellent stock of older, mid-rise rental apartments right along Queen, and an overall greater variety of housing options than the remainder of the East End. Of course, Woodbine beach is a major draw, and the Jazz Festival really puts the neighborhood on the map. Riverdale along Broadview is another excellent area.
Aside from those two, however, I feel that each of the remaining individual neighborhoods make poor cousins to their western counterparts. East Chinatown vs west Chinatown, Danforth vs Bloor, Little India vs Little Portugal, etc. That is, of course, not to say that they aren't worthwhile on their own, or that they do not contribute to Toronto's great variety and vibrancy. It's just that in the context of this thread, along the imaginary Yonge Street divide, this is how I would personally allocate preference and perceived prominence.