There's Kanthal, Nichrome, and NI200 nickel wire. Kanthal and Nichrome are fairly similar, but Nichrome is is lower resistance (20-40% less) so it heats up faster and burns hotter than a similar Kanthal build - e.g. with similar gauge and wraps. But I've read that some people think Nichrome doesn't last as long and is more expensive than Kanthal. Kanthal seems to be the most popular wire used today.
NI200 is much lower resistance than both Kanthal and Nichrome and is much softer. NI200 is required for temperature control functionality on
devices like the DNA40.
I use Kanthal for most of my RDAs and NI200 on a few RDAs that I like to use on my DNA40. I'm actually starting to prefer NI200 because it's so easy to wrap.