SSD is kinda mandatory for a fast PC nowadays
I would say NVME SSD.
NVMe SSD are very fast indeed, but truly are only incrementally faster than a SATA3 SSD. The impact in performance for most workloads is small. Granted, in some cases, that improvement is very important, but in most cases, it isn't so important. For most tasks, SSD disk access time is already so fast that even doubling or quadrupling the disk performance doesn't give such a great actual overall gain, all things considered.
In contrast, the performance difference between even the fastest HDD and an ordinary SATA SSD is extraordinary. The SSD is literally 3 orders of magnitude faster in terms of latency and operations per second, and several times faster in data transfer (MB/s). Just replacing a HDD with SSD can decrease boot time from say 2 or 3 minutes (to full usable desktop) down to 20 seconds. That is HUGE. Swapping that SATA SSD for a NVMe one (if the system can even boot from one) might reduce the boot time by another 5 seconds, maybe 10 tops. Noticeable, sure, but not mind-blowing like the change from HDD to SSD. When you already boot in just 20 seconds, you can't exactly shave 1 minute off the time, can you?
I've been trumpeting the benefits of SSD for years to my friends and coworkers, ever since buying my first 60 GB SSD several years ago. Each and every time one of them has finally upgraded to an SSD, they remark that its "like a brand new computer". I'd say that SSD is mandatory, and NVMe is a "would be nice".