I put off reading Lois McMaster Bujold's Vorkosigan Saga for a long time due to the terrible covers, but I highly recommend them!

I'm reading them in the author's recommended reading order and I'm currently up to The Vor Game. While the first Cordelia books are decent the Miles books are real page turners so far. So if you were put off by the cheesy looking covers like me, give them a go!