I know it is a strange question to ask, but I'm curious - was it released as free in the past?

http://www.uesp.net/wiki/Daggerfall:Files. So's [removed].

Yes, you can download both TES1: Arena and TES2: Daggerfall from www.elderscrolls.com
http://www.elderscrolls.com/arena/
http://www.elderscrolls.com/daggerfall/

I've been also interested in getting into one of those games. Do they require dosbox? Are there some recommended official, unofficial patches for them? I hear both of them are quite buggy still (as are most bethesda games on release).

Daggerfall should be available with a pre-configured version of DOSBOX. That is, of course, unless you have an old DOS-based PC or a machine set up to run actual DOS. A boot CD or ancient Floppy Disc might also work, if you have the proper version of DOS.

For me both Arena and Daggerfall apparently installed dosbox on game's installation, and work without me having to configure anything.

Not sure how officially patched up Daggerfall is, but here are the patches and the Unofficial Patches

http://www.uesp.net/wiki/Daggerfall:Files

Also, if you notice the game is unresponsive, like you can't move or climb stairs, then you need to slow the CPU down in DOSBox. I think 20,000 is the common value, but you may need to set it even lower on your rig. Just keep that in mind.

As linked above (and I'll link http://www.uesp.net/wiki/Daggerfall:Files again), there is a "Daggerfall Setup" download on that list which will work on newer Windows systems and will install Daggerfall + Official patches for you. Plus optional Unofficial patches, fixes, and addons (if you so wish to have them).

And even AFTER installation, a Daggerfall shortcut will be made for you on your desktop and other places. This shortcut with automatically do all the boring DOS stuff and open Daggerfall for you in less than a second.

I highly recommend getting that Setup. I did the other way once before where you gotta use DOSBox and use commands and such... A PAIN in the butox, that was! I do so love this setup way much more!

Link wise, you ninja'd me. But at least I mentioned the main Daggerfall setup file (Everything you need in one installation file! Woohoo).

~Edit~

Though most people probably don't notice that setup file since it is kinda new... (It was released in 2013 on the month of August) so... Eh.