The advice below is based on my experience in enterprise class computing. When you make your living playing poker, or even if you do it just for fun but have a lot of money on your online accounts, it's important to have the most reliable computing platform available.
It should go without saying but I'm going to say it anyway. Never use the remember my password feature.
When you finally do connect you're on massive monkey tilt and shoving any two cards. It's fairly simple to make your internet connection more reliable.
APC Back-UPS is a good choice for networking hardware. It's like a surge protector with a built in battery that helps protect the equipment from power issues and provides back up battery power in the event of a power outage. These are great for little hiccups in power or short outages but are best used as a temporary step before your backup generator kicks in for extended power loss.
Redundant Hard Drives
An ideal setup would be to install an additional PCI SATA controller in your computer so you have two. One from the motherboard, one from the card. Use 2 SSD drives for the best performance and set them up as mirrored drives through software. I've been using the OCZ Vertex SSDs on different systems and very happy with them.
Install the drives in a mobile rack. The ICY DOCK ToughArmor MB994SP-4S Mobile Rack is a good choice and very durable. It makes it easy to swap out drives if they fail but more importantly allows you to easily remove the drives for storage.
When you're done playing poker, pull the drives out and put them in your safe until the next time you are playing poker. If you want to use the same desktop for other computing you can have a different set of drives for that. Keep your poker rig for poker only. Don't install IM, Skype, or other software that's not related to poker. Don't even browse the web or check email. Keep a laptop nearby that's on your "public" VLAN for that.
You'll also want a separate UPS for your desktop and monitors. Get the biggest one you can afford for the most run time.