I'm a firm believer in the High Yield series - unless you're studying for months for Step 1, I think the retention rate for reading through something like Lippincott is very low. Honestly, between High Yield Pharm and First Aid, I don't think there were more than a handful (literally) of questions on QBank or the actual USMLE that couldn't be answered with those two sources alone. Personally, I think going through something like High Yield Pharm 3 or 4 times will yield you a higher score than going through Lippincott once. But then again, people have their own study style. If you feel like you need the context provided by a larger book, by all means, use something more exhaustive. Although I only used High Yield Micro and Bug Cards for microbiology, I would recommend using Clinical Micro Made Rediculously Simple because it's easy reading and those crazy diagrams/cartoons are cheesy, but you'll never forget them. When it comes to Board studying, knowing the basics very well is far better than knowing everything semi-well.