MTGNexus

I think that "Guild's of Ravnica" and "Ravnica Allegiance" would be good choices, both have pretty obvious draft strategies in them being focused on five two-color pairs each, thus making them relatively easy to draft, both sets also have some pretty fun legendary creatures for commander stuff. The sets are also filled with goodies for commander, that although not necessarily as powerful as some older cards are still quite useful in commander, in particular the mana rocks and nonbasic lands are pretty much staples of the format these days.

Alternately, going with Throne of Eldraine and the latest core set (2021) is also a possibilitiy, both are in my experience very fun to draft, and can lead to some crazy fun matches. They also have a lot of fun cards for the commander format, adventure in particular is good for the format as the cards with it serve double purpose as both a useful spell and a creature.

In general, and if you have the money for it, any of the old Ravnica sets make for good draft experiences, or if you want to try out tribal drafting, the original Innistrad set.

I second Guilds of Ravnica and Ravnica Allegiance due to boxes still being relatively new and available. As well as the easy themes of drafting/building around guilds.

A lot of the newer core sets have themes built around colour combinations and are designed for newer players to understand, since their power complexity is often lower.

Ikoria also had some more fun mechanics such as mutate which could be fun to make a build your own monster type deck.

I have no clue how much boxes of either the Ixalan sets would be but they also had some cool tribal themes

Ikoria's new but fairly complex. But at the same time, I think almost anybody would find mutate fun just noodling around on the kitchen table.

The obvious answer here is Core 2021. But I'd say Dominaria and War of the Spark are good recent options too.

Dominaria is also a really cool choice. It can serve as an introduction to the "original" Magic World and also ahs soem cool mechanics and themes to it

Dominaria's an amazing pick, so many good possible Commanders in it and it's a fairly high power set. but I have to admit I didn't know it was still in print, I think you'd have to buy it at a premium.

Personally I think Throne of Eldraine and War of the Spark are two of the most powerful modern magic sets there's ever been and they're full of interesting commons too. They're not great for land though and sadly when you learn about how regular players build decks, you might find yrself caring about land more than anything else x3