Bicycle
Previous bicycle was a Surly Troll with the bees knees of components: Rohloff Hub, SON dynamo, Tubus Stainless steel racks, Avid BB7 disk brakes, etc..
Wonderful bike, but it was causing me problems. So I sold it and my current bike is exploring the low cost end of cycling. The K-Mart bike cost $99 brand new. I've outfitted it with the components I need.
Gear
One person's essential, is another person's junk. My gear list is what I'm carrying. It may not be what you want to travel with.The goal is to have as little extra stuff as possible and have a comfortable time travelling. Rolling along the flats it doesn't matter so much, but head up hills or try lifting it up and down stairs, and it matters lots. Less weight is also less wear and tear on bike components.
In my dreams its only my bike and nothing else. When I wake up, reality hits.
I'm travelling about in Australia and I don't have a fixed home - so everything I really "need", I have to carry with me. This means that some items I choose are heavier than other options, because I want the longer life the heavier duty the item gives. Some things are cheaper in bulk, or can't be purchased in small quantities - so I have "extra" for a long time. Add in that I like the "less peopled places" and this means that services and parts are a long way away. So I carry things that I would leave behind if I were on a shorter trip, or travelling in more populated areas.
Weather conditions vary a lot. My current gear is to try and cover a reasonable range. I expect that I'd need to add more winter gear if I end up in a cold place for too long.
I'm still working out what I "need" as opposed to - "you have to have", "you should have", "I'd like to have", "it seems a good idea", or some other reason. Its good to ask "why do I have this?".
One day I'll get it just right :)