Previously IBM was considered to have the best build quality. I still think their high end business class models are pretty good. HP is also good, especially their business class series (EliteBook , ProBook etc.).
I'm not sure what Thinkvantage does, but I'm sure you can find an alternative 3rd party product that can do the same. Don't put too much emphasis on bundled software; look at the hardware, build quality and price instead.