Okay, well I'm less familiar with mac games since I'm still on windows, and so I haven't been keeping track of mac releases, of which there have not been many, indeed Mac wise most of your available games will be things like browser games and muds which are platform independent.
Ios wise however there is lots of stuff around, even if several landmark titles have been lost to Apple's ruthless update policy.
If you want a great arcade title, try Feer, an absolutely awesome game about avoiding zombies.
There are a few audio adventures and 3d first person games kicking around such as a blind legend, blindside and the eerplay titles,. as well as several audio adventures rom ticon blu such as the inquisitor series and the space invaders game space encounter, but the where the Iphone exells are in rpgs, gamebook adventures and strategy games, especially since voiceover can be used to create very accessible games.
Rpg wise there is the very awesome king of dragon pass and its sequel six ages, though these are pretty in depth. There is then the more casual rpg land of livia, the extremely good strategic battle game path of adventure, and the two very dark text rpgs a dark room and the ensign.
There is then the stratogy war game a few minutes of glory, and Nano empire from the same developer, as well as the strategic card game lost cities, and the rather unique puzzle collection black box.
If you want pure strategy, you could try the very awesome knight commander and crafting kingdom, as well as the other titles from woodside aps which range a completely accessible tetris game, to a version of mine sweeper and a word search puzzle.
if your looking for interactive stories, there is a host of amazing stuff from choiceofgames and hosted games (also available online), and the delight games library, not to mention the phenomenally awesome timecrest.
there are then the two great social hub collections, gmaeworld and diceworld, which let you play games from ludo to word searches to trivia questions to a host of dice games across the internet, and a large selection of titles from Blindfold games which run the gammet from traditional games to sports and arcade titles and usually make interesting use of the Iphone's hatpics, though beware since some of these can be quite pricey.
There are probably some I'm missing, and a few, such as the first person adventures from somethinelse which are sadly unavailable now, but these are the ones that immediately occur to me at this point.
Also note that www.applevis.com is a site devoted to discussion of accessible aps for Ios and mac, containing podcasts and other information, so that also come in handy.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)