T5x0 (Avoid the T540, the touchpad buttons are supposedly shit.)
I'm running a T530. Max out the ram, get a ssd, it's great. I'm probably on my third one, I keep buying junkers for $50 from eBay for the parts. I majorly abuse it. The magnesium frame likes to crack near the heatsink, the steel frame around the screen likes to crack 1 inch above the hinges, don't spill water on the table it's sitting on.
I'm running a T530. Max out the ram, get a ssd, it's great. I'm probably on my third one, I keep buying junkers for $50 from eBay for the parts. I majorly abuse it. The magnesium frame likes to crack near the heatsink, the steel frame around the screen likes to crack 1 inch above the hinges, don't spill water on the table it's sitting on.