It's turning into one of the biggest shopping events of the year, yet some discounts are better than others.

The 48-hour Amazon Prime Day extravaganza ends at 2:59 a.m. ET Wednesday (11:59 p.m. PT Tuesday) after offering more than 1 million deals, including intermittent "lightning deals," to members.

For example, the Toshiba HD 43-inch Fire TV Edition Smart TV is now $179.99, a $120 savings, while supplies last.

Nearly 8 in 10 back-to-school shoppers mark their calendars with the Amazon event, according to the National Retail Federation.

"It's worth it if you are looking in general for something," said Michael Bonebright, a senior blog editor at DealNews. However, "if you are looking for a very specific thing, like a computer monitor or backpack, that may not go on sale."

Not surprisingly, Amazon devices, in particular, such as the Echo or Kindle, will be deeply discounted. (Prime members who haven't tried Kindle Unlimited can get the first three months of unlimited reading free when they sign up, according to RetailMeNot.)

More from Invest in You:

What hiring managers want to see in your social profile

Save a shocking amount of money when you buy these five things

These people in their 30s are doing a simple thing to get rich

Subscribe to CNBC on YouTube.

But don't count out home goods, Bonebright said. Last year, one of Amazon's best-selling Prime Day items was a six-quart instant pot for $59. This year, the pot is priced at $55.99.

Shoppers can also save up to 30% on some Amazon-exclusive household items and an additional $10 off $40 pantry orders with the code "pantry," Bonebright said.

That brings a 24-pack of Presto paper towels down to $32.89 — about $8 less than the price of Bounty at Target. Target is hosting "Deal Days" on Monday and Tuesday and is similarly pushing its in-house brands, while other major retailers like eBay are also advertising sales.