Yeah, this is basically what I think as well. I considered Beatles album openers when I made my list, and thought of Come Together. I love the song, and Abbey Road is my favorite of their albums and, on certain days, my favorite album by anybody ever - but, yeah, like you said I don't think of it really as such a great opening song.
My favorite Beatles opener is probably either Taxman (the weed cough at the start is fantastic) or Two Of Us which is just achingly poignant, to me, and I always picture it as John and Paul singing about eachother.
I would also like to confess that my actual Top 7 would probably include both Where The Streets Have No Name and A Sort of Homecoming, but I didn't feel like putting them in my original list.
I also am troubled by the lack of Thunder Road selections in this thread, because it is the greatest song of all time. Thankfully IWB and phanan came to the rescue and listed it.