I have battlemats from Wizkids, Dwarven Forge, Mats By Mars, Paizo, Books of Battlemats, cardboard terrain tiles (they did another release for 5e), and Chessex.
A basic Chessex mat is a classic, and you can get them in hexagonal or square grids, and in a variety of colours. And then you draw whatever you need on them. Basic, but tried and true. They are roll-up.
Paizo mats are gorgeous but because they are fold-out, they have seems and are hard to lay totally flat, if that is an issue (like if you are using miniatures. As mentioned, putting a sheet of clear plastic or plexiglass on top works wonders.
The Wizkids mats are for terrain and are made of neoprene, like a mouse pad, so you can't draw on them. But they are gorgeous! They are roll-up.
Mats by Mars are the best, IMO. They are high quality vinyl, with a wide range of options and sizes. They work great with terrain and you can draw on them with dry erase. They are roll-up, but the weight of the vinyl allows them to flatten out quite well. Edit: also, they will make a bespoke mat just for you if you provide the image.
The 5e versions of the terrain tiles were released with a city, dungeon, and wilderness set (I have all three). They require more work but allow for a lot of options and reuse. As mentioned, you'll likely want more than one set of each terrain type.
The Dwarven Forge mats are beautiful, and designed to work with terrain. The are roll-up, but thin, so easier to flatten. They do the most realistic water wats, IMO. DF also offer terrain trays, which are metal trays covered with a terrain-styled fabric (so lava, cavern, ice, etc.). They are designed specifically for magnetized terrain, but I have used them as battlemats for small builds and they are fantastic because you can pre-prepare them and lift them to and from the table. But expensive!
I think the various Loke "Books of Battlemaps" are a fantastic option. I have several that I use for "away" games. They come in various sizes and offer a lot of different terrain types, plus extra 2d terrain features that you can add to a map. They are on Amazon.
But there are lots of other options - Monster Fight Club, Gale Force 9 come immediately to mind for making quality mats designed to work with scatter terrain.
TLDR: If had to recommend just two, they would be Mats By Mars and Loke's The Gigantic Book of Battlemaps.