Each business day, TheStreet.com Ratings TheStreet.com Ratings compiles a list of the top five stocks in one of five categories -- fast-growth, all-around value, large-cap, mid-cap and small-cap -- based on data from the close of the previous trading session. Today we focus on mid-caps.These are stocks of companies that have market capitalizations of between $500 million and $10 billion that rank near the top of all stocks rated by our proprietary quantitative model, which looks at more than 60 factors. The stocks must also be followed by at least one financial analyst who posts estimates on the Institutional Brokers' Estimate System. They are ordered by their potential to appreciate. Note that no provision is made for off-balance-sheet assets such as unrealized appreciation/depreciation of investments, market value of real estate or contingent liabilities that might affect book value. This could be material for some companies with large underfunded pension plans. First Financial ( THFF) is a bank holding company whose subsidiaries provide various financial services in Indiana and Illinois. It has been rated a buy since August 2006 because of its solid stock price performance and net income growth. For the fourth quarter of fiscal 2008, First Financial reported weak revenue results, but declining revenue does not appear to have hurt the company's bottom line. Earnings per share improved from 49 cents in the fourth quarter of fiscal 2007 to 55 cents in the most recent quarter. Net income also increased, rising 12.4% from $6.4 million to $7.2 million. In addition, cash and cash equivalents increased from $74.3 million to $76.8 million.