Prime Day (now not just an amazon thing?) ends tomorrow, so I scanned Wirecutter's Prime Day page for plausibly-actually-life-improving purchases so you didn't have to (plus a couple others I found along the way; excludes tons of areas that I'm not familiar with, like women's clothing or parenting):

Seem especially good to me:

• Their "budget pick" for best office chair $60 off
• Whoop sleep tracker $40 off
• Their top pick for portable computer monitor $33 off (I personally endorse this in particular)
• Their top pick for CO2 (and humidity) monitor $31 off
• Crest whitening strips $14 off (I personally endorse this in particular)
• 3-pack of their top pick for umbrellas, $12 off
• Their top pick for sleep mask $12 off
• Their top pick for electric toothbrush $10 off
• 6-pair pack of good and super-affordable socks $4 off (I personally endorse this in particular; see my previous enthusiasm for bulk sock-buying in general and these in particular here)

Could also be good:

• A top hybrid mattress $520 off
• A top inner-spring mattress pick $400 off
• Their top pick for large carry-on $59 off
• Their "budget pick" for weighted blanket $55 off
• Their top pick for best air conditioner $50 off
• Their top pick for laptop backpacks $45 off
• 3-in-1 travel charging station $24 off
• Top pick for face sunscreen $16 off
• Uber/UberEats gift card $15 off (basically free $15 if you ever use Uber or UberEats; see my previous enthusiasm for these gift cards as sold at 80% face value at Costco here)
• 4-pack of Apple AirTags $15 off
• Their "budget pick" for bidets $12 off
• Their top pick for towels $10 off
• Good and super-affordable portable Bluetooth speaker $8 off
• Top pick for portable mosquito repellent $7 off
• 3-pack of good and super-affordable sunglasses $4 off
• Many, many mechanical keyboards, headphones, smart watches, wifi extenders, chargers/cables, and gaming mice if you're in the market for any of those