I'm currently taking an intro to Java programming class and the Prof is suggesting we use Jgrasp. He's open to us using other IDEs. What are some good ones y'all use?

IntelliJ

Jetbrains products like intellij, webstorm and phpstorm are my favourite

Vim with eclipse jdtls

Eclipse ir netbeans

I vote for Intellij.

Not light, not cheap (but you're a student so you should be able to get it for free with the Jetbrains student license, along with all their other products) but damn the out of box experience on it is so damn good, and with some extra plugins it's an absolute pleasure to use.

Plus the derivative jetbrains ides (Rider, CLion, Pycharm, Phpstorm, Webstorm etc) are also seriously damn good and they're all based on the same intellij core.

Intelij ,pal.

IntelliJ is probably the most full-featured with features that actually work (unlike Eclipse which is a bloated clusterfuck of shit, and NetBeans which was behind with the times last I checked).

I use VS Code because I do development in a variety of languages (Java, C#, Python, Javascript being the main ones) and it has fairly good support for all of those so I don't have to keep switching IDE's

@RememberMe IntelliJ community edition is free for everyone.

Another vote for intellij

I loved IntelliJ while I worked full time with Java, as well as AS3, and C, but since 2018 I've been all about the front end world, meaning VS Code has taken over my computer.
It offers support for a lot of languages, but I've found features break down quick, as the size of the project increases.