Obenauf's Heavy Duty LB is the only thing I use on leather. Gloves, belts, work boots, everything. It temporarily darkens leather but it always returns to its normal colour as it dries, and I've used it on light tan/blonde gloves. It does a better job of conditioning leather than anything else I've tried and it contains an anti-mold ingredient as well as beeswax for waterproofing. It's pricey but a tub lasts me for years.
Before I switched completely to Obenauf's I used Hot Glove Cream Conditioner. Not the godawful oven treatment, just the conditioner. It seems to be Wilson Prostock Conditioner that's rebranded, it comes in an identical tub and the product literature is the same. It contains lanolin, doesn't darken leather, and smells like a brand new wallet.