Au contraire, Hitler and the Nazis are great analogy material for exactly the reason you stated: Everyone is familiar with them, so they are the perfect stand-in for <bad people> in any analogy. I'm not sure what you mean about the baggage, but an analogy always compares specific similarities between two otherwise different things, and therefore there will always be irrelevant differences, aka "baggage". If the listener insists on highlighting these irrelevant differences, what can the speaker do? Example:

Person A: John wouldn't do anything evil like that. He has a family and kids!

Person B: Well, let's not forget that Hitler also had a family and kids.

Person A: John is not Hitler!

Person B's analogy is perfectly rational and effective. He's making the point that simply having a family and kids will not stop people from committing even the greatest evils (and therefore probably not lesser evils, either). However, Person A ignores this obvious line of reasoning, and instead focuses on a total strawman: assuming that Person B said that John === Hitler. But what could Person B have done to prevent this? Simply not using Hitler wouldn't work:

Person A: John wouldn't do anything evil like that. He has a family and kids!

Person B: Well, let's not forget that <some other bad person besides Hitler> also had a family and kids.

Person A: John is not <some other bad person besides Hitler>!

Person A is still factually correct in his final statement, yet it's still a total strawman. If he insists on employing this reasoning, then it's impossible for Person B to ever use an analogy, because an analogy always uses as its subject two different things, which are by definition not the same as each other in every single way.