When choosing an LED lamp, the first thing is the base: E27 is the large standard screw, E14 is the narrow one, and G13/T8 is for long tube lamps. The base must match your fixture, or the lamp simply will not fit.
Shape is a matter of aesthetics and place: candle (C37) and globe (G45) lamps look good in chandeliers, the standard pear shape is for general light, and T8 tubes replace old fluorescent lamps in kitchens, garages and warehouses.
Brightness is measured in lumens, not watts: a 40 W incandescent equals about 5 W of LED, a 100 W about 13–15 W. Choose the colour temperature to suit the room, and CRI 90+ where colours and faces matter. Electrica and EL Light lamps come in every base and shape in the catalogue — the "For Long Life" way.
