At the moment I have Samsung Galaxy SIII. I think it has been a year since I bought it. I won't be copy/pasting specifications here, you can see them in any phone review site, but I will talk about it.
The first thing- size and design.
In my opinion it could be a little bit smaller, kinda hard to operate with one hand owning regular sized thumbs. Problems is with reaching top-left corner, luckily there isn't much functionality in top-left corner.
The whole design- I love it. Pebble shape is very comfortable in hand (at least when i'm not trying to reach top-left corner). Phone have smooth edges and it is pleasure keeping it in hand. The myth about cheap plastic- I have to admit, it is true. Back of phone really looks like cheap, and plastic very fast have scratches and looks old. But positive side to plastic compared to metal- it is always warm, and that is what I like about it. I have held phones with metal covers- the first cold touch, I don't enjoy it. or when you put that cold phone in your pocket, just next to your balls? Yea, that is nothing you would enjoy.
Galaxy SIII is pretty powerful phone, with 1GB of RAM and quad core processor. You won't have any problems running demanding apps, or playing games such as GTA on phone, but the downside- someone has to feed that processor, and it won't be fresh air and positive thoughts. Battery is draining pretty fast- about 4-5 hours browsing web, 2-3 hours for demanding games, such as- Max Payne, GTA series and the newest 3D games- even much faster for MMORPG games. So getting power bank should be something you consider for longer trips. But battery is enough to live through day. Also built in power saver helps a lot, it is very great, best i have seen so far, really extends the battery life if you are not using phone very often.
Built in OS android 4.2.x is bad, really bad, the worst. It is too damn heavy even for such powerful phone. If you know something about root, custom ROMs and all that cool Android stuff- just get another ROM like me.
It is smartphone, you won't be able to play football with it. I have dropped it few times- luckily just some scratches. I'm always using protective plastic for screen, so it is like new even after year, and I suggest you too. Mainly because it helps keeping Gorilla glass tough and scratch free, but it is your choice.