I've always been a fan of earbuds. They are just more convenient and comfortable to use when out walking/cycling/catching the bus. I use Sennheiser ones that have these little wings on them, which allow you to kind of twist them into your ear so that they stay in place properly.

Their sound quality is awesome! Much better low frequency response than your typical iPod bud (based on the pair i got with my 3rd gen ipod all those years ago) and they are clear when played at the loudest volume of my player (i use a 4GB Zen).

Before that i had a pair of Audio Technica buds that i bought from a store in Perth and they also produced excellent quality sound. However, they didn't have the little wings on them, so they didn't sit tightly in your ear, which meant less bass response and also much easier for them to pop out while running. I'd still be using those buds if it weren't for the cable fraying -- never wrap your buds' cord tightly around your player!

Anyway, back to the question at hand: ear buds all the way!

Definitely earbuds when on the move. I've gone through a few in-ears - some comfortable, some not so much - and I'm currently using the SoundMAGIC PL30 (which I reviewed here - http://www.goodgearguide.com.au/review/headphones/soundmagic/pl-30/275088) which are fantastic for the price. I would have preferred a little more noise isolation, but the comfort and sound quality are great.

At home though, you just can't pass up headphones for quiet listening.

Good question.

When out and about (cycling, gym etc) earbuds much more convenient,but compromise sound quality for convenience.
Cannot match quality of on-ear or over-ear headphones - but these are most suitable when at home or on public transport.

Ear buds are lighter and more portable, you can stick them in your pocket and go. Some of them these days offer incredible sound quality. Because they plug into the ear, they do block the ouitside noise somewhat.

As for headphones, they are heavier and more bulky, but they do block outside noise a touch better while trapping the sound.

Richard
www.telecomsuperstore.com

I have used a fair few different cheapy brands of earbuds, but my favourite so far is a pair of in-ear Creative EP-830s, they look great and i got them with my Zen X-fi which i've moved on from to an ipod touch (which has horrible earphones and horrible EQ audio quality!). The Creative in-ear buds cut through the crappiness to an extent :P they do the job very well, providing awesome bass, and highs so crisp and clear it just really brings any music to life. The one disadvantage is some bass-heavy songs (namely rap songs that focus on car-exploding bass) get a bit muddy, then you need a decent powerful sound system for those songs.
But yeah, they're my favourites for portability, discreetness, and of course the noise-isolating qualities. I've had them for a few years now, they're pretty reliable too, and retail for only like 40 bucks here in australia.

You just can't get the same value for money or portability with a big pair of fancy noise-cancelling headphones..or a boom box :D