This is so hard to specify because it really depends on a lot of factors. It's usually more like there are specific models that are really worth getting, or pricepoints or brands depending.
Like, I don't think cordless drill/drivers that are sub $100 are really worth it if you're ever going to do more than screw into pre drilled or pre made screw holes. But a Bosch (blue), Dewalt, Milwaukee, Makita, etc are all pretty good. They're just usually over $100.
You're right about blenders - I never had a use for Oster blenders, but a BlendTec in 2008 changed my life (well, not really, but did do things that I have uses for at least).
Ohh, pressure cookers - I don't want to risk it exploding, so I avoid the $70 and under crowd. Actually, I went Kunh Rikon which is pretty expensive, but also really hard to screw up (like 6 layers of safeties), and easy to get refurb parts for seals and such.
Lots of safety equipment - there's all sorts of ... "fake" in that it won't actually work stuff at super cheap prices. I'm thinking like laser safety glasses or chain saw safety pants. Mid range is def worth it there.
Dishwashers IMHO. I've used cheap ones before and they clean poorly and are extremely loud. Depending on your house, you won't want to be in the next room to them. OTOH, Bosch higher end ones, like the 800 series, cost a pretty penny, but are darn near silent and actually live up to the washing claims - shit just comes clean in them. I'm usually surprised in a good way. Oh, and that third tray for silverware - I'm never going back to the basket (though lots of brands have that now).
Stand Mixers - especially if you want to get into bread or attachments for grinding things. I strongly recommend the Bosch Universal Plus. That thing is like a power tool for the kitchen. We've abused it for over 10 years and it's not slowing down. I know many people online who have had them for 30 years.
Vacuums - look into Sebo.