Vanderbilt now has a private platform for accessing ChatGPT along with other models. Though technically still in pilot form they are granting access off the wait list usually within 1-2 days.
Login (if you already have access): https://www.vanderbilt.ai/
To request access (if you do not have it already) go to this registration link.
Although there are many models, the links below represent those that are at or near the same level of performance of Open AI's GPT-4, generally considered the most capable model currently.
Anthropic's Claude 3 - Available via Pro Version for $20/month.
Google's Gemini 1.5 - Available to try for free, then pricing varies.
Papers
Cousera Courses: