1920x1080 for main pc, 1600x900 for my current laptop
My previous main laptop has 1024x768, it's very workable especially with the fine-tuned font sizes etc (and it makes picking wallpapers way easier as an aside, opens up so many older wallpapers that are otherwise awkward at both high sizes and 16:9) and I still got plenty of use out of it as an excellent Win2000 machine after getting a new laptop but at the moment it's sadly out of commission due to both the battery and the charger croaking
16:9 is the biggest crime to ever happen to monitors.