Recently on business trip to Chennai stayed at V R Homes, Mylapore (they have two such guest houses in Chennai). The one at Mylapore is located on Radha Krishna Salai, right at back of hotel president. Two reasons to stay there are location and reasonable price.
Most of old city commercial places, offices, tourist attractions are in immediate vicinity.
Place is moderately clean, reasonably priced and accessible to all sorts of transports. More