Shure & Etymotic pretty much rule the roost when it comes to in-ear. I have the Senn PX-250's and they are surprisingly good (bought 2 pairs at AA, great reurn policy as well).

What I don't like about them is the thick-pen-sized battery pack and the fact that they don't fold up very small. For light-packed traveling, that's not really ideal, but if you don't mind the size, then they are excellent.

I sat next to a Bose owner on my last trip and we swapped phones for a few minutes. While the Bose do a better job of isolation, they don't sound as good IMO, although he did not agree (big surprise). I think if you listen to them side-by-side w/o outside noise, you'll find that the Senns are a bit better, but if you factor in the noise isolation, the Bose may be a better value.

I've been intrigued with the Shure EC5's, but I just can bring myself to blow $400+ on something that small.