Don't see why these would not run on an XP system.

This list of games ranges a good decade as far as I can see. This will turn into people recommending you build multiple computers if you want to play the games on time period accurate machines.

Off the top of my head, psychonauts is going to require a beefy 1+ ghz system. A quick search on Syberia 2 brings up Windows XP + 1.5GHz + DirectX 9 for recommended specs.

If you want ONE system that will run all of these games, I would look for a socket 478 Pentium 4 with the usual suspects in graphics (Radeon 9800 pro, GeForce 4xxx or 5xxx as a starting point, but there are plenty of systems that could do this. You can dual boot this system with win98 and winXP if you like. The only issue you'll run into is sound on older DOS based games, i'd just go with dosbox for those.

Let us know what you aim to do and we can help further selecting parts.

I think if you scratch off Syberia 2 and maybe something else (not big on 00s adventures but I did play through Syberia 1 on a Pentium 2), you might get what you want with a mid Pentium 3 rig. Just make sure it has an ISA slot for an SB16 of some sort. Most of the games in your list should even be fine with a Pentium MMX, though.

Except for those 2 Windows XP+ games on your list, a pentium 3 board with an ISA slot and a geforce 4 would be my best bet

I have an Asus P3B-F with a 1.4GHz pentium 3 and ISA yamaha audician 32 plus sound card. Makes for excellent DOS (non-speed sensitive games) and 9x

If you didn't need the DOS sound support, you'd be alright with a pentium 4. Of course you could use a pentium 4 and dosbox instead.

Since you're going to be mixing in alot of DOS games, in addition to the recommendation of an ISA sound card, I'd think an Nvidia GPU would also be a good bet. they have great DOS compatibility, and anything upwards of a Geforce 256 should have ample power to play the more modern games in your list.... I'd try to aim for Geforce 4 series or better though just to be safe.
https://gona.mactar.hu/DOS_TESTS/

Wow you guys are fast. After a little thinking I most likely going to build three different computers (DOS? 3.1? 98 and XP) as I want to play games on "time period accurate machines".

I would like to start with a Windows 98 machine since I did most of my gaming on that OS.
Should I go for a Pentium 2/AMD K6-2 or a Pentium 3 machine? I'll leave my XP machine to an AMD CPU.
Is a ISA slot for sound card important or can I stick with a PCI sound card and AGP video card. Is that even possible for Windows 98?

My list of games to eventually play is actually a lot bigger since throughout my teen years I come to amass many PC titles from trades/buying/selling. I have about 50 big box titles I never touched but want to play. All in all I have about a few hundred games in my parents basement waiting to be unboxed. Found this on a shelf covered in 10 year old dust.

If you split off the DOS era to another system - with ISA Sound card, then you could use PCI or even onboard for Win98.
If I recall correctly, my Win98 system was an Athlon Thunderbird, with a variety of GPUs tried Rage 128, Savage 4, finally a Geforce 2MX and later an 4MX 440 that I picked up cheap - not sure if that had my SB16 sound card to begin with, but certainly finish with PCI128 and then a cheap Live.
For DOS/Win3 I had a 486, VLB CL5428 and the SB16.

It also depends if you need a period correct SLOW DOS for things that are speed sensitive, or a higher performance system to cover the last hurrah of DOS gaming - in which case, it may be better mixed with the Win98 and that means ISA sound card, or one of the PCI card and motherboard solutions with good DOS compatibility.

The other "golden" for DOS (if any of the games support it) would be a Voodoo card - but the days when I could have snagged one for a fiver (oh God, why didn't I - well at the time, Glide was dying to D3D) are long gone

If you go with a P3 for your Win98 PC you may get away with using it for DOS as well.
ISA sound is important if you boot into true dos, However a P3 with a SB Live or later or Aureal vortex will be able to play dos games from within Windows.

If it was me I would go with a slot 1 P3, that way you have a fast Win9x PC with decent PCI soundcard and AGP graphics., but you can also drop back to true dos with a ISA sound card and and even play network games with your dedicated dos PC.

AGP and DOS is fine, in fact quite a few AGP cards make real good dos cards with great visa support.