Assigning current direction in mesh analysis
The equation for clockwise should be:

$$-v_{s} + (i_1 + i_s)R_2 + i_1R_3 = 0$$
$$-v_s + i_1(R_2+R_3) + i_sR_2 = 0$$
$$i_1 = - \frac{ i_sR_2 - v_s}{R_2+R_3}$$

Which is exactly negative of the other direction choice.