The way I see it, there are two basic kinds of villains in superhero stories.
Type A is the villains who match the hero in power and ability, either through having the same power/talent or by having an ability that counters the hero's own.
Type B is the villains who are symbolic of everything the hero is not.
You tend to get a lot more of the Type As, but it is the Type Bs who are truly dangerous because they have to face the hero, not as equals, but from a defensive position. They can't match the hero as an equal so they have to find some way - through trickery or planning - to neutralize the hero and exploit their weaknesses.
You can go through the various pantheons and make a list to see the point. Superman has Bizaro, Doomsday and a host of other powerhouses for Type A and Lex Luthor for Type B. Batman has Scarecrow, Two Face and a host of other people who utilize fear as a weapon against their enemies... but it is The Joker who truly mirror's Batman's power to inspire fear and twists it into a weapon against order.
Green Arrow has a lot of Type A villains; master marksmen (like Merlyn or The Red Dart) and villains who can make him unable to use a bow (Count Vertigo or Auntie Gravity) but he's never really had an truly effective Type B villain.
So where do we go in creating such a villain? Back to the Robin Hood legends that inspired our modern take on Oliver Queen, of course.
Amazingly, we don't have to tweak a lot to look at the modern Arrow Family and see a new band of Merry Men.
You have the disposed noble son turned bold outlaw hero. -> Oliver Queen/Robin Hood
You have the lady fair and true love, more than capable of holding her own in a fight -> Dinah Lance/Maid Marian
You have the red-stressed right-hand man. -> Roy Harper/Will Scarlet
You have a monk who would prefer a life of peace, but stands ready to fight when needed -> Connor Hawke/Friar Tuck
I admit there's no clear parallels for Mia, Cissie, Sin or Lian... but most of the modern takes on the Robin Hood legends allow for there being a fair number of MerryWomen and young children being among those peasants who united under Robin of Locksley's banner. So I think I can be cut a little slack on the metaphor.
My point is that while Ollie has been painted as a modern-day Robin Hood by many a writer, nobody has taken the rather obvious step of playing up to that legend in order to give him a worthy enemy.
Enter John Prince - a captain of industry from an old money family and every bit the charmer Oliver Queen was back in his days as the CEO of Queen Enterprises.
Mr. Prince breezes into Star City with a fist full of cash, a lot of promises about revitalizing the local industry and a controlling interest in the Star City Rockets. He hasn't got much business experience, but he does have a pedigree and a reputation based on his graduating at the top of his class at Harvard. Between that and his boundless charm, it's easy enough for him to sell the city on his first plan to help the city; build a new stadium for the Star City Rockets.
Of course financing a new stadium will require a tax increase; the Rockets can't pay for it all themselves! And of course they WILL need the city to use the Eminent Domain laws to buy up the land for the stadium which - sadly - will necessitate relocating a few hundred people out of the substandard housing that Mr. Prince's associates have determined would be the most beneficial place to build a new stadium. To say nothing of all the work that will have to be done widening roads and building bridges to accommodate all the extra traffic the stadium will generate... but hey, it will bring jobs into the city.
Minimum Wage Jobs. Six Months out of the year. No benefits. The kind mostly worked by teenagers looking for work experience and immigrants looking for a slice of the American Dream.
It's a bandage on a cancer and Oliver Queen is one of the first to say so. He's also one of the few who will say so, with most of the city being firmly behind the new stadium, thanks to a public campaign financed by Mr. John Prince pleading to people's civic pride and saying that a half-cent sales tax increase really isn't all that much when you're talking about an investment in the city and your childrens' future.
Naturally, the only futures John Prince is concerned about are in his stock portfolio. Because not only does he own a controlling interest in the Star City Rockets, he also has quietly bought up a number of contractors outside the area; contractors who will, miraculously, win the bidding for the construction jobs on the stadium, the roads and the bridges. And since John Prince is signing their paychecks, he can be assured of every expense being spared in the construction of the new Star City Stadium as more and more of the city's money is funneled into his pockets.
It's sleazy. It's crooked. And there's not a damned thing Oliver Queen can do about it as an activist or a hero.
Ollie does win some support among the friends and family of the neo-Homeless of Star City - all of whom were cheated out of the fair price for their homes since the agent doing the appraising was in John Prince's pocket. But once the vote is passed and the tax increase is approved by the people, there's nothing anyone can do but howl at the winds and curse John Prince's name. And there's precious little of that as John Prince, with his perfect blond coif and bright smile, starts appearing all around town at different charity events. He doesn't ever seem to donate anything but he does appear at a lot of events. And the people love him for it.
How can you be a defender of the people when they don't want your protection? This is a question Green Arrow - and the rest of the family - will have to address as John Prince begins to use his money to make things more difficult for the local vigilantes...