Reapply.
If you do it soon and send ALL the required documents, you could have your visa and be in the UK within a matter of weeks.
If you appeal, you're looking at about a year of waiting, possible lawyer fees and it may go to court... and even then, it's extremely unlikely it will be successful because if you didn't include the right documents, then they made the right decision to refuse the visa... which means you'll just have to re-apply after that anyway, and the visa fees will be several hundred pounds more by then (they are increasing in April with the NHS levy).