There are a lot of great versions of Lex Luthor to choose from:
* The Lex from Elliott S! Maggin's novels Last Son of Krypton and Miracle Monday, a fascinatingly rich, almost heroic character, a supergenius who could've brought a technological utopia to humanity if his ego hadn't compelled him to devote himself to battling Superman. He saw Superman's power as a dangerous imbalance in human society and dedicated himself to being the restorer of balance.
My absolute favorite version of the character, bar none.