I enjoy all aspects of Eve so really open to just about anything here, done exploration, PVE, PVP, industry, etc. What will make me the most ISK an hour if I only have a budget of 100 mil for a ship plus the equipment needed?
I would suggest not throwing all your money into one ship with your entire budget, you lose it and will then feel so despondent you will probably quit.
What do you enjoy doing in game?
Is there anything you want to try yet but have not?
Try different things, you will enjoy some more than others but you will get a collection of activities that you enjoy and you can mix and match to get the most from the game.
get a smaller ship that will last longer, if you can at least do L3 missions, you can get paid to run missions by the United Standings Improvement Agency. Folks have made enough money to sub Omega without paying RL cash.
Get yourself 10 Herons and 10 Ventures 
Either look into Exploration or look into Homefronts. Homefronts can net you 100 million isk per hour if you get with a good fleet.