if you talk about price and specification,
any brand will deliver the same thing, may be the price different

but...think about technical support, how about IBM, NEC, Toshiba and etc?
i think only DELL will support you on next day (no delay)
if you have any problem for your system, call DELL Technical Support after lunch today, DELL engineer will arrive to your doorstep next morning and do troubleshooting or part replacement (anywhere in this world including ISRAEL) did NEC, Toshiba, Acer do the same?