I did a similar search a few months ago and there are surprisingly few “Mac compatible” (allows for transfer to a Mac and records in an accessible format) recorders that are readily available at a decent price.
I settled on the Olympus WS series, the model I got at the time was the WS-110 but the current equivalent is the WS-321M that has an MSRP of $99.
It’s a great size, does a good job of recording (I used it for press at a really loud backstage event once and it picked up great) but the best part is the ease of transfer: the bottom half of the recorder will actually detach to reveal a USB connector that you just plug into your Mac and the recorder just shows up like a USB flash drive with all your recordings that you can just drag over to your Mac.
The one issue is that the recordings are encoded in .WMA format but I got EasyWMA that makes it very easy to convert the recordings to MP3. iTunes may also do that as well… (I wasn’t able to find other recorders that recording to MP3 while also meeting my other criteria of price/performance/Mac-transfer)
So there you have it – I chose the Olympus WS series for it’s easy Mac-compatible transfer method, excellent recording performance, good value, and is commonly available online and at brick stores.
Oh and if you want to be able to ‘work with’ the recordings on your Mac I’d recommend 2 choices of Mac audio software: Fission by Rogue Amoeba or SoundStudio 3 by Freeverse. They’re not too expensive and are really easy to just pickup and start using to cut your recordings, remove background, boost vocal volume, etc.