Back to Shadow Warrior 2.
What an underrated shooter this is. It has weird and funny characters and moments, a huge arsenal of weapons that can be modded, variety in enemy types, great graphics, classic/arcady gameplay and I'll be damned if this isn't one of the few games that does procederal generation right.
In case you enjoyed the first Shadow Warrior like I did, give this game a chance, it improves on the first game in nearly every way.