Trying to find a graphics card for around $200 that will give me the best performance in AutoCAD, Revit and Lumion. It will be paired with a Haswell i5 and 16GB DDR3. Any recommendations?
Is Nvidia or AMD is the market leader in this market?
Some viable options:
Radeon R7 260X $179
GeForce GTX 660 $209
Radeon HD 7850 OC $159
You will be surprised how good the i5's HD4600 is. Depending on your specific work and expectations you may see little improvement in putting any card in it. I suggest you start without any of these and see if you are happy.
Note that all of the GPUs you list are for gaming, they will work for this use, but the benefits won't be amazing. You don't mention memory type/amount in your list which is a big factor, assuming they are all the same the 7850 is by far the best deal.
If you want to be a big hit at LAN parties you'll need a dedicated graphics card!
1: By big hit do you mean people care what other people use at LAN parties?
2: As long as you can play the games it doesn't matter, and the LAN parties I go to a HD4600 would actually be fine (most recently played Monaco, WC3, Risk of Rain).
3: AutoCAD, Revit and Lumion are not games and I'm not aware of people breaking them out at LANs.
Lumion 3D will definitely need something more powerful than the HD4600. Have tried running it with a AMD Radeon 5770 1GB and it severely struggles unless the resolution is turned right down.
According to http://lumion3d.com/faq/#graphicscard
If you aren't happy with a 5770 you probably won't be happy with the GPUs you listed. The 260X is only a little bit better, with the 660 being the most powerful (and expensive) on your list, but it really isn't going to change things completely from a 5770.
Honestly I use Autocad on my GTX 670 with a Samsung 27" and I don't have any issues at all. I've never used AMD on autocad so I couldn't tell you how they go.