Onset temperature (solidus), T_m and offset temperature (liquidus) T_l of melting of a series of bulk glass forming alloys based on Zr, La, Mg, Pd and rare-earth elements have been measured by studying systematically the melting behaviour of these alloys using differential thermal analysis (DTA) or differential scanning calorimetry (DSC). Bulk metallic glass formation has been found to be most effective at or near their eutectic points and less effective for off-eutectic alloys. Reduced glass transition temperature T_rg given by T_g⁄T_l is found to show a stronger correlation with critical cooling rate or critical section thickness for glass formation than T_rg given by T_g⁄T_m.