If you're a frequent flyer or a heavy spender, the United MileagePlus Club Card is a great deal. It's a premium card with a hefty $395 annual fee but that pays off quickly. For starters, you get free year-round United Club access (a membership costs $475) and two free checked bags on every flight. Since you earn 1.5 miles per $1 charged, the best of any airline card, it works out very well for heavy spenders who can offset the fee or anyone who uses the lounge enough. Use this link and you'll get a $95 statement credit. If you want a lower fee card, the United MileagePlus Explorer Card gets you 1 mile per dollar, one checked bag, priority boarding and two one-day club passes plus up to 40,000 bonus miles but with no fee for the first year.