I've repaired many motherboards afflicted by the capacitor plague, usually with capacitors salvaged from other boards.
Speaking of vintage PC hardware I've replaced the memory slots on a 486 motherboard and the cathode ray tube on an IBM PS/2 Model 25, and some minor resoldering of QFP chips & broken traces on PCI video cards here and there. Old hardware tends to be pretty robust even when stored in non-ideal conditions.
I don't repair PC power supplies unless they're something really special, they just pile up in my junk box as parts donors. Even though I could I don't consider it worth my time.

What I really love is bringing CRT TVs and monitors back to life. 😊

Both my Amiga 4000 and Macintosh Portable have had capacitor replacement done.

http://www.youtube.com/watch?v=ZTij3AT7Mkw
http://www.youtube.com/watch?v=TDCaKHof_bI

I have also recapped more modern hardware like an LCD panel.

I've recapped many boards (particularly Tantalum caps which seem to love failing in a spectacular fashion) and replaced the odd corroded connector. Probably the most intricate solder job I did was replace a broken 68 pin PLCC CPU socket on an old 286 motherboard. My soldering still looks pretty rough around the edges though.

Would love to have a go at re-capping a motherboard!

I guess one needs a good source for caps and knowledge which ones are good to go for. And practice on some dead boards before you work on the good boards.

caps are easy to find... jaycar shops stock the common types, you can order the more exotic types online from http://au.element14.com/ or http://australia.rs-online.com/web/ or lots of other places 😀

but yes practice on something unimportant before trying for real. If you apply too much heat you can strip the tracks and solder pad from the PCB, then it can be a real pain to repair...

Iam soldering everything if its needs to replaced.. Maybe i am not a professional, but actually iam not stupid too.
I have a good soldering station from weller, that gave me a lot of profit on easier soldering..

What i soldering so far, on the most boards the failing batterys.. In one i have replaced it with a coin socket, because the board lets you know that it also could accept coin sockets.
I soldered on some boards a new keyboard connector, because the old was very much ruined *losing parts in socket*

What i now iam going to do is to replace the jumpers (Turbo, reset, led, led ect, keylock) on my St Juko clone motherboards for angled ones, otherwise they are sitting in the way with larger cards..

I also wants to replace some simm sockets thats are in bad shape, and a motherboard with a broken fan clip on a socket 7 motherboard. But for that finer work a need to have better equipment for it.. So
i also want to upgrade the weller solder station with a 50 watt iron and some tips for both 50watt and 80 watt irons.
I am also looking for a desolder station to desolder the harder parts.