There's a lot of different kinds of wine and they go in and out of fashion. More than that different wines can be very different within categories. I personally dislike merlot... a lot.
Oddly enough, some of the best wines and worst wines I've ever had were both sub-$10 chianti.
Good rule of thumb - if you have a go-to red and a go-to white at under-$10 and under-$30 you will be ready for damn near any adulting-grade social engagement for people who make six figures or less.