I'm using a DAW with Sonar. ESI 192M PCI card (4 in, 8 out). XP Pro - I've stayed away from Vista completely, and judging from the horror stories I've heard, that's still a wise choice. I've gone as software based as possible for everything and the only things I don't DI are acoustic guitars and vocals (which I don't do much of these days anyway). Outboard I'm trying to keep it as simple as possible and gradually upgrading quality as I go, I'd rather have better quality than more features/inputs. AT some point, I'm hoping to be able to stop spending money on guitars & software and getting a chance to spend more on recording hardware.
Soundcard is important, but if you have a decent audio interface already, and don't need the extra inputs & outputs, you should rather look at upgrading your signal path by getting one decent two channel mic preamp. You can still use your mixer pres for those occasions when you need more inputs (drums), but you'll find the bulk of your recording needs will use only one or two channels, and even when you are recording a band live, just having a higher quality pre for vocals will make a difference. In fact, whenever you can, record direct to audio interface, bypassing the mixer entirely. I only use a mixer for monitoring.
Also, if you are recording acoustic instruments and voice with a mic, look at spending a little money and effort on getting the room sounding better. A few grand thrown at acoustics will make much more of a difference to your recording quality than spending the same amount (or even more) on interfaces, pres or mics. An added benefit in the smaller one-room studios most of us tend to have is that your monitoring quality and consequently your mixes improve vastly.
You don't mention which Rode mic you have. Ideally for acoustic guitars, small diaphragm condensers like the NT5s are going to work best, although you can get really good results with any decent condenser. I've been recording acoustics using a combo of a Rode NTK (large diaphragm, tube) and a small diaphragm AKG condenser and getting fairly good results, but I intend on upgrading sometime to a pair of NT5's (which come in matched pairs, BTW). Acoustic guitars are not a priority for me though, so that's fairly far down the (long) want list. A decent pair of condensers also work well as overheads for a drum kit, so they don't go to waste.
Electric, I've gone DI these days, using a dedicated laptop with Native Instruments Guitar Rig and then digital from that to the DAW. I have Ampeg SVT for DI'ing bass, but I usually just record a flat DI'd signal and use it as an insert effect, rather than print directly to tape. (HA! I think that last phrase just gave away my age). Then it can be changed at any stage of the recording process. I'm keeping my eyes open for a small, high quality recording amp like a Cornford Carrera, but that's more just to have than because I need it. I'm waiting to see the new Peavey Windsor Recording amp - that might do the trick.
Article on recording acoustic guitars: http://ratcliffe.co.za/articles/hsacoustic.shtml
...and electrics: http://ratcliffe.co.za/articles/hselectric.shtml