The best option would be a venue that that someone is willing to donate to your cause, but, if you are unable to find such a place, choose a site that gives you the most amenities for your budget.
Don't be afraid to shop around and always ask if the owners or managers would be willing to throw in "extras"-like coat checking, valet service, or hot hors d'oeuvres-as a donation. Keep in mind that if you choose to hold your event at a location that does not already have a license to sell alcohol, you will likely need a special license from the municipality where your event will be held.
Always take advantage of the free and low-cost ways to market your fundraiser: press releases, notices in Church bulletins and community message boards, and flyers handed out by volunteers, are all ways to advertise that will not strain your budget. The type of event you are holding will determine the type of beverages you need and whom you should contact.