Are you asking bare metal or virtualization?
If bare metal then are you asking for PCs built by a vendor or one you can build yourself? The only way to get a "best" (whatever that is) PC would be to build it yourself unless your "best" requirement is pretty low.
If virtualization used then you can run Windows 2000 w/KVM on the latest and greatest and use passthrough for KB/mouse/audio/video/etc.
Verified various Operating Systems on newer hardware w/KVM via proxmox
PROXMOX TEST 2000/XP/Vista/7/8/10/11/Linux
CPU: Ryzen 9 5950x
CPU Cooler: Corsair iCUE H150i w/ 3x Noctua NF-A12x25 PWM chromax
Motherboard: MSI Meg X570 Unify
NIC: Intel Ethernet Converged Network Adapter X550-T2 (10GB)
Memory: G.Skill 32GB DDR4 PC4-28800 3600MHz Ripjaws V for Intel CL16 (16-19-19-39) Dual Channel kit (2x16GB)
GPU: 8800GT 512MB (2000 Vanilla)
EGPU: Zotac Geforce GTX 980 Ti 6GB AMP! Extreme GDDR5 ZT-90507-10B PCIe (Windows XP,Vista)
EGPU: GIGABYTE Gaming OC GeForce RTX 3080 10GB GDDR6X PCI Express 4.0 ATX Video Card GV-N3080GAMING OC-10GD (rev. 2.0) (7+)
Video card: EGPV-1101-C1 M.2 (Proxmox Console)
Audio: Realtek® ALC1220 (Vista+)
Audio: Creative Sound Blaster Audigy PCIe RX 7.1 (2000/XP)
Monitor 1: Acer XB271HU 27" 2560x1440 "Acer Predator XB1"
DVD: Blu-ray LG WH16NS60
SSD: Seagate FireCuda 530 1TB
SSD: Seagate FireCuda 530 4TB
PSU: CORSAIR RMx Series, RM1000x, 1000 Watt, 80+ Gold Certified, Fully Modular Power Supply
Case: Corsair 600C Black ATX Full Tower Computer Case w/ 3x Noctua NF-A14 PWM chromax
EGPU 980TI
Cable: ONE XPLAYER OCuLink Cable for OneXGPU eGPU, SFF8611, 3.3ft Long, PCIe 4.0 x4
Adapter: NFHK 4X Oculink SFF-8612 SFF-8611 to PCIE PCI-Express 16x Adapter with ATX 24pin
Case: Fractal Design Ridge Black - PCIe 4.0 Riser Card Included - 2X 140mm PWM Aspect Fans Included - Type C USB - m-ITX
PSU: Corsair SF Series, SF750, 750 Watt, SFX, 80+ Platinum Certified, Fully Modular Power Supply (CP-9020186-NA)
Occulink card: PCIe x4 Gen4 with ReDriver to OCulink 4i Host Bus Adapter
EGPU 3080
Cable: ONE XPLAYER OCuLink Cable for OneXGPU eGPU, SFF8611, 3.3ft Long, PCIe 4.0 x4
Adapter: NFHK 4X Oculink SFF-8612 SFF-8611 to PCIE PCI-Express 16x Adapter with ATX 24pin
Case: Fractal Design Ridge Black - PCIe 4.0 Riser Card Included - 2X 140mm PWM Aspect Fans Included - Type C USB - m-ITX
PSU: SilverStone SX1000 1000W SFX-L:
Occulink card: PCIe x4 Gen4 with ReDriver to OCulink 4i Host Bus Adapter
PROXMOX Test DOS\9x (VESA)/NT4 (VESA)/2000 (XP+ Backup)
Processor: Intel Core i7 6700k
CPU Cooler: Noctua NH-U9S w/2 Noctua A9 92mm fans
Motherboard: ASUS PRIME Z270-A
Memory: Patriot Viper 4 32GB (4 x 8GB)
NIC: Intel X540-T1 10GB
SSD: Seagate Firecuda 530 1TB (Proxmox)
SSD: Seagate Firecuda 530 2TB (Proxmox VMs)
PSU: Corsair RM850x
Audio: Creative Sound Blaster Audigy PCIe RX 7.1 (9x/2000/XP)
Monitor: Dell Ultrasharp U2410F 24" 1920x1200
GPU : Geforce GTX 780 (2000 BWC/XP+)
GPU: Geforce FX 5200 128mb (9x-NT) (2k-xp for games that need it)
Case: CoolerMaster ATC-110 w/ 4x Noctua NF-A8 PWM fans
Amebay 5.25 Inch Front Panel USB Hub 2port 3.0, USB 2.0 for Computer Case
DVD: Blu-ray LG UH12LS28