I always talk about or concern myself with what stocks will provide the best risk-adjusted returns over a 5-year or longer period, often seeking a double-digit annualized return.
Nonetheless, asset allocation is equally important. Most investment advisers will tell you that 80/20 (equity and bonds) is standard if you're in a younger age bracket, which is then slowly shifted to 80/20 (bonds and equity) as you approach retirement. Essentially, you swing from growth to income. Some advisers may also push you into other areas such as alternative investments, high-yield bonds, commodities, inflation-protected securities, real estate,