I'm considering starting a saga next month, and was looking for some inspiration. Of the adventures that have been published for Ars over the various editions, which ones are the best? Which have the most interesting storylines, the best writing, and so on?
If it matters, my preference is for the mythic and folklorish aspects of mythic europe.
Hands down, the very best is in Ancient Magic concerning the Language of Adam. Mainly because it is so open ended. I mean, there is definately a line of progress. But it is essentially non linear, because you can just wander around and "discoer" adventure. In otherwords, the plotline is not forced on the story. It is a sandbox style setting. You don't even have to introduce Adamic. Just have fun in Babylon!
Second best, IMHO, is in Ordo Noblis from 4t edition. The Merits of Twilight and Gloaming.
Oh! My actual favorite, and the only one I actually payed rather than just read; Icelandic Wards, the PDF based on Land of Fire and Ice. I actually canabalized the adventure and turned it into something useful for my saga, bbut the challenges and fantastic elements were still there. It took three archmagi and over a queen of vis to defeat Pan Caudrax.
It depends on what you are looking for...
Most Ars adventures are episodic and quite a few are intended to run over a period of game years as sort of mini campaigns. If you want something like that, The Tempest and Faerie Stories are both quite enjoyable and suitable for pretty much any covenant.
For more traditional "have an adventure" stories...
The Merits of Twilight and Gloaming in Ordo Nobilis is excellent. I liked the other adventure in there as well, so its two good adventures even if the bulk of the book is outdated game mechanics.
Deadly Legacy is quite fun, too.
Broken Covenant of Calebais is a good solid dungeon type adventure (and 5th edition even).
There are other adventures that are good, but without knowing your group it would be hard to say if they were suitable for your players. Adventures like "Cause and Cure" and "Festival of the Damned" go over great with some groups and not so well with others.
Black Death I like as SG, but I've never actually run it. My players have always taken one look at the set up (investigate a plague stricken town/covenant) and said "Screw that idea". 
Oh! Ghoul of St. Lazzare/Festival of the Damned! I played that one too, long-long time ago. That one is also excellent.
I'm currently playing in a saga set in the Novgorod Tribunal, from the "Lion and the Bear" tribunal book. The storyteller has used the setting as is, and we're having a ball. Having not read the book, I can't say how much of it is written as "adventures" per se, but the overall tribunal plotlines are great.
As an SG, I really have enjoyed running "The ghoul of st. lazar." I haven't run "The Tempest" but it does seem very adaptable and fun.
Ars Magica doesn't have too much in the way of "bad" adventures. I'm not overly fond of A Winter's Tale and The Fallen Angel, but the rest range from good to excellent.
As I mentioned before, though, it depends on the tastes of your players. A good number of the adventures are written to be multiple episodes over a period of years, with other adventures in between. One or two are completely non combat. Several are very heavy on combat.
The fallen angel and the old 2nd/3rd edition adventures are extremely linear: you follow the plot as described or you ar eunlikely to ever solve the problem. In fact in some of them you are herded in that direction using a shovel, so the evolution is far from smooth between scenes. So old material can be considered to be rather DnD-ish kind: move forward, follow blindlyu tbhe track and hack & slash when challenged. Cool, if you like that kind of stuff. bad if you like more open ended stuff.
Other adventures like those in ancient magic have to be viewed with a grain of salt. The magical novelties they introduce can cause BIG changes in the core setting as described. Teleport around the universe or render magical defenses useless are important consequences of some of the introduced breakthroughs in Ancient Magic, for example. As such be careful before intrducing adamaic or some such stuff in your game. it also have important metaphysical consequences your players might not enjoy.
For me the best adventure must still be the broken covenant of calebayis. i have played it twice and directed it twice more. Even knowing the whole plot is a damn incredible adventure. In one case it ended with our covenant destroyed, in an other with the magi settling in calebais. A third time they developed a strong enemy and in an other they developed that same enemy into an ally and a former neutrral into an enemy! In each case it worked really smoothlty with our current saga.
The ghoul of saint lazare is a good one and I particularly enjoyed the ones in Ordo Nobilis. Note that a lawyer (I have one in my group) might turn you upside down and beat you with a stick as a SG if you are not careful with one of those adventures, though! 
(it happened to me to the overall laugh of my players, the bastards 
)
Under the current setting, for me the best adventure seeds are already in the rulebook, though. The section on storyguiding and the world of Ars Magica is simply AMAZING as story potential.
Ars Magica tends to work providing you with background information and story seeds. That makes it easy to spin adventures out of the given material without the neded for specific adventure books. I like that 
Cheers,
Xavi
Interesting.. I'd've said that Calebais is the most D&D/Dungeoncrawling of all the adventures (I don't consider this a flaw, btw). You do realize that Calebais is one of those "old 2nd edition adventures", right? Its gotten rewritten for 5e, but its pretty much identical.
I have the 2nd/3rd version of the adventure both in English and Spanish (the Spanish edition is a work of art, BTW) and the current 5th edition. I am aware of that, yup
Yep. It is a dungeon crawl, but it has significant differences.
The main one is a design one: the plot is far from linear. That isa majopr advantage of the adventure: it being open ended it can be fully exploited without taking the "normal" and "predicable" paths.
In most "dugeon crawl style2 adventures what you have is an adventure that goes "A then B trhen C then D". If you deviate from that sequence of events the adventure book leaves you out of options. They force you to follow a path like that. Fallen Angel IMO follows that structure so it is much more DnD style than Calebais IMO. It is a question of options, not specific setting
Cheers,
Xavi
Festival of the damned, because of the two plots
Well, I think you've read a some bad D&D adventures if you think that's what a "D&D" adventure is all about. The classics of the field (Against the Giants, Temple of Elemental Evil, Keep on the Borderlands, etc) are at least as open ended as Calebais; generally more so.
The avoidance of "funnel" quests has long been a standard bit of DM advice. Fallen Angel is, indeed, a funnel quest which is why we both put it on the not so good list. A Winter's Tale I think just has bad encounters.
Deadly Legacy, on the the other hand, is sequential but there is a tremendous amount of roleplaying and decision making options to take along the way.