There has various opportunities for a laptop or a desktop but everybody does not choose both above. My first choice is desktop. What is your first choice?
Absolutely a Laptop.
If you can afford it the macbook pro has consistently been the best laptop you can buy for the last 4-5 years.
Why do you prefer desktop? And do you use a desktop, or do circumstances impose to use a laptop?
Please answer these questions to give the thread some chance of becoming interesting. If it turns into a list of laptop/desktop answers it’s going to be closed real soon.
Me, I don’t have a preference. I use a laptop, because I don’t work always in the same office. I prefer a “desktop” keyboard and screen, though, but that’s easily solved when I’m in the office: I just plug the laptop in a docking station.
Actually I have a Desktop & also a Hp laptop. I know there are many opportunity to use a laptop But if you want to change the configuration of a Desktop probably it is so easy. So my first choice is Desktop although I have a laptop.
I prefer to use a desktop, I like to use my hands as they were intended and like Guido mentioned typically they have better screens and full sized input devices, etc. Usually they also are more easily customisable.
I dislike laptops so have a Netbook instead, which is far more portable and useful to how I work if having to be on the move. Given the choice I would choose the Desktop to work on in nearly all cases though obviously you cannot lug desktops around in your hand without it getting tired.
I prefer to use a desktop. I can worked fast on desktop than laptop. Though Laptop is easy to carry anywhere.
I prefer to use a desktop with a multi-monitor setup, but I also have a 13" notebook.
A good question to ask would be: how do you like to work? In one designated place, or are you moving around a lot where a laptop would be necessary?
I like my desk top with my 22 inch screen and both a wireless mouse and keyboard.
I’ve never felt comfortable typing on a laptop.
Very close to my setup too. I prefer a desktop, simply because I like having a multi-monitor setup (plus I hate most of the keyboard layouts on laptops). Instead of a notebook, I actually use a 7" tablet (works for most of what I would utilize a laptop for).
I like laptop.It’s my first choice.It’s easy to carry and I can use it even inside my car.At home,I’m using a desktop.
In terms of computing power there isn’t much real difference between laptops and desktops, apart from possibly laptops not using I7 processors. Laptops can easily be used as a desktop replacement with the use of an external monitor and mouse and keyboard (I personally hate using them mouse pads that all laptops have). The only thing that laptops may struggle with are high end games like GTA4 and Skyrim. If you’re only looking for surfing the net and sending emails on the move then a laptop would probably be overkill and many could get away with a netbook.
Ofcourse Laptop 
I prefer desktop because it is better for me !
You can easily use an i3 for web development, and possibly bump that up to an i5 if you work with photoshop and multimedia with some frequency. An i7 is really only necessary if you’re doing a lot of 3D rendering or video production and conversion.
If you don’t have a personal preference between laptop or desktop, then the question comes down to price–for the same specs with high-quality hardware, which is more cost efficient? Also keep in mind that your ability to upgrade a laptop is somewhat limited, while a desktop is usually easier to upgrade. Generally, I can get 10 years out of a desktop with periodic hardware upgrades, while I struggle to get 5 years out of a laptop before performance becomes a serious issue.
I will still prefer Laptop. Not only because of portability but also the durability of today’s laptop.
Desktop. Massive dual screen setup, more accurate colour reproduction (very few laptops including the MBP I have, have IPS quality screens), more accurate and quicker input via mouse and full keyboard. Also, far better speed and price to performance ratio for heavy work like video rendering. I’ve no idea how anybody can work productively and quickly on a tiny single screen of a laptop. I enjoy using my MBP, it’s a nice bit of kit, but when I really need to get-stuff-done it’s not an option.
I always like laptop because it is easy to take away from one place to another.It is also easy to use than desktop.
For the work I do, Web Design/Development, I am happy with my Macbook Pro. I prefer laptops for so many reasons - it is portable, it is clutter free (extra keyboard etc…) I love minimalist work space. I CANNOT wait for the day that I can get rid of my clunky desktop and cables and power strips.
I can see for other work like 3D and video that a desktop would work great - yet in the Mac family though.
Will go laptop…
My laptop connected into my 22" monitor works great for me. The laptop is powerful for everything I need it to do, and my files are with me wherever I am. I used to have a desktop and I would have to sync my files between the two…kind of a pain.