O.k. I'm not a Mac users, but a Linux users so anything I post here is only a suggestion. First off I'm a straight Linux guy, I own a copy of Windows 98 but haven't got it installed and have no intentions of doing so just to play games.
Anyway I play all games through
Wine which what Crossover was (is?) original based on so hopefully games that work via Wine on Linux should work equally well on Crossover on Mac.
As I said, I play solely through Wine on Linux and have had a pretty decent success rate at getting games to work. For example, I've just finished The Lost Crown which is not only an awesome game but works flawlessly in Wine. Before that I've played through and completed without problems, both Syberia games as mentioned above, Post Mortem, Still Life, The Moment of Silence, Secret Files: Tunguska, Barrow Hill, Rhiannon, Fahrenheit, FBI: The Art of Muder, the first 2 Agatha Christie games (had problems with Evil Under the Sun) and loads of others I'm probably forgetting.
It's helpful if you have a good idea which engine a game uses as well, developers seem to reuse them on their titles. The Lost Crown uses the wintermute engine, as does several other games I've tried such as Barrow Hill. This engine seems to work really well under Wine and as such I've managed to play Barrow Hill without problems (but haven't completed yet). So if I know that a new games uses an engine I've not had problems with before I'm pretty confident about buying it and getting it to work without many problems.
It's worth mentioning copy protection, as you've done with the adventure shop. You're right that this is a problem for Wine/Crossover, a lot of copy protection doesn't work, which is a great shame (and one that might not be solved anytime soon for various maybe obvious technically reasons). Sometimes it worth trying to googling a game and find out before hand what copy protection it use and make sure it's one Wine/Crossover can copy with. Wine has a list of the current status of which copy protection works and which does
here, but I believe Crossover has slightly better support for this, but not by much.
I mentioned googling a game to find the copy protection because it's important to realise it almost always the publishers that decide on which copy protection to use (if at all) not the developers. Which leads to some strange situations. I said previously that I've played and completed The Moment of Silence, but here's the thing. I first brought EU DVD version of the game which just wouldn't work, due solely to the copy protection. It wasn't until after I googled around I found that the US 4 CD version of the game doesn't use any copy protection. A quick shop at Amazon.com and a few weeks later I was playing the game with out any problems.
Oh I mentioned engines before, which reminds me the first two Discworld games both use the Tinsel engine (Discworld Noir uses a 3D version of tinsel). There's work going on by the scummvm people to get that engine working within ScummVM, see
here for a little bit of info, I've heard reports that it's working well so I might grab a development version and give it a try.
Oh yes you've mentioned ScummVM, but no love for Serria games?
MacFreesci and of course
Freesci.
Finally don't forget there are the occasional Mac and Linux native versions of games, the
Penumbra series spring to mind, but personally I'm not a fan (FPS action/adventure).
As I said, this is all Linux based, but given Mac's unix history combined with Crossovers Wine history hopefully it should means your experience should be pretty similar when it comes to emulating Windows games.
