The best sewing machine for you will depend primarily on what you intend to use if for. If you plan to sew mostly clothing, you'll be best off with an electric or computerized sewing machine. For embroidery, a dedicated embroidery machine is ideal. These usually come with a package of designs, with more designs available separately.
If you plan to both sew and embroider, the best option is a "crossover" embroidery and sewing machine. These are computerized models with hundreds of computerized stitches, plus a library of embroidery stitches. The required embroidery hoop is also available.
If you plan to sew mainly knit fabrics, a serger may be your best choice. These machines sew a stretchy overlock stitch and automatically trim the seam allowance while they sew.
For quick repairs, a hand-held mini sewing machine will suffice.
At Walmart, you'll find Every Day Low Prices on a wide variety of sewing machines and accessories.