Remember Reading Rainbow? It's sort of like that...

I have a problem... I can't seem to finish a book to save my life...I'm currently in the middle of 4 different books right now, and this is just fiction. I need your help to determine which one of these I should finish first. Or, if you want, leave spoilers in the Comments section - that way I don't have to finish them. I'm reading the following:

Eldest - a continuation of the coming of age tale of a boy and his dragon Saphira
Trading Up - written by the creator of Sex And The City - a story about a looney model in NYC
Coma -this scares the crap out of me, and is holding my attention above all the rest. A medical thriller about people suffering brain death after going in for routine surgeries to never wake from their anethesia.
Confessions of a Shopaholic - this one just hits too close to home at the moment and had to be put down.