[quote name='lilman']The Hori screen protector is a must:
http://www.amazon.com/Nintendo-3DS-Screen-Protective-Filter/dp/B004K6LQ9E/
Once it's on, you can't even see it anymore (well, I can see mine since there are two bubbles on the top from lack of adhesive, but at least the bubbles aren't on the screen).
You will probably want to add something to keep the bottom screen lip from scratching the top screen. The default pads are too short. I took two rubber feet from my 360 and put one in each of the top screen corners. They add just enough height that the bottom screen can't touch the top. I don't even notice they are there anymore.
Club Nintendo offers a great 3DS game case for 250 coins:
https://club.nintendo.com/rewards-details/a/24002.do
You'll get 160 coins just for registering your new 3DS. Each 3DS game should get you 40 coins (30 for registering, 10 for post play survey a week later).
I don't know which is the best 3DS case as I don't carry mine with me too often. I went with this soft Hori case for home:
www.amazon.com/Nintendo-3DS-Compact-Case-Black/dp/B004K6LQ80/
Has slots for 3 games. It's soft cover so I wouldn't trust it in a bag or backpack. Hori makes a hard cover version but it's bulkier:
www.amazon.com/Nintendo-3DS-Hard-Pouch-Black/dp/B004K6LQ7G/[/QUOTE]
Is it true the Hori screen protector makes the touch screen a little less responsive? I'm on the fence about getting one so I've just been using that thin foam sheet that Nintendo put between the screens in the packaging.
Some accessories I picked up for my 3DS are the 3DS Aluminum Shell plus Stylus Pens Kit - Gray by Hyperkin & the GreenBulb 3DS/DS Lite/Dsi/DSiXL XStylus Crayon Transforming Wide Grip Stylus Pack. I'm still testing out the xstylus crayon to see how well it works versus the original. It fits in the same pen slot on the systems however is much wider. And the shell is good quality. Strong, light-weight and doesn't scratch the system when you put it on. Just really annoying to remove.