And I read a really good one today. It's called Wrong Twin, Right Man by Laurie Campbell and it's a Sihouette Special Edition from October of 2004.
Anne and Beth are twins, who go on a yearly vacation together and this year there's an accident and one twin dies.
I'm sure you can see where this is going but they get the twins mixed up. They think Beth is dead and Beth's husband, Rafe, brings Anne home while she's recuperating. They figure out the switch pretty early on, more than half-way through.
It made me cry and I couldn't put it down.
I'm not very coherent but if you can find it, it's an excellent read.