ok so why do people take about Vanguard so much around here? Is it better than fidelity?
The average Vanguard fund will cost you less than the average Fidelity fund, so from that perspective Vanguard is better.
You can find Fidelity funds (their Spartan series) that are comparable to Vanguard's lowest cost, so from that perspective they are similar.
If you have >$250K invested with Fidelity you might (not sure if your 401k employer also had to use Fidelity for HSAs) be able to have a no-fee HSA at Fidelity, so from that perspective Fidelity would be better.
When I roll it over, what account is it in? Roth IRA?
That is up to you, but if you roll a pre-tax 401k over to a Roth IRA you pay tax on the entire amount in the year of the rollover.
Telecaster's advice is good. Fidelity will likely be easier for you because the funds are already there. That said, rolling over to Vanguard will still be easy:
https://investor.vanguard.com/401k-rollover/.