There really isn't one right answer to this question. There are a wide range of fundraising ideas that can be a success for you if you keep the right things in mind while you are organizing, such as the size of your group and the kinds of financial goals you have. If you are in charge of a relatively small group of fundraising participants, for example, then you probably don't want to choose something where shipping charges will cut into your profits, or where minimum order requirements will make you anxious.
Your customer base is another important consideration with sports club fundraising. You may be tempted to go with something simple like chocolate bars, and certainly you can have a lot of success with a sports club fundraising idea like that. But if, for example, you know that your customers are mostly going to be older people, you might be better going with something like tea or coffee, just to tailor your sports club fundraising activity to the people you intend to sell to. Likewise, if your customers are likely to be kids, something like candy or other snacks can work really well for sports club fundraising.
There's really no end of ways that you can plan your sports club fundraising effort - have a look at our sports club fundraising ideas pages and get some inspiration for the sorts of things you can do. If you have any further questions about your sports club fundraising, contact your fundraising consultant for advice.