Panniers?

I got this rack (TorTec Tour)

and this pannier (Altura Urban Dryline 17")

I carry my laptop, power supply, lunch, shirt, waterproofs (if it's not raining) and assorted junk to work. It's never leaked even in the heaviest rain. The bag mounts diagonally on the frame for increased room at the heel, and even with my size 11s I rarely touch the bag with my shoe. The laptop compartment has a removeable, padded, zip-able inner, with a handle. It's all very well made with massive rubber corners on it to protect the contents. I've spotted no loose seams or missed stitches.

The bag mounts with a really easy drop-in system, and has a big red button to release that's not fiddly even with freezing cold fingers. It's fairly well clipped in at that point, although the fittings do need re-adjusting every now and then. It's never fallen off, although if you hit a curb a bit hard, or drop off a high curb then the lower clip can slip outside the rack, but even then it's still well attached enough to not cause a panic. This is usually the first indication that the fittings need re-adjusting as it's been allowed to slide at the top a little.

The fittings can be covered with a roll-up / zip-down flap, that, while not exactly luxurious, at least keeps the mud and wet off your back when you shoulder the bag. The strap is long, extendable, unclippable and well padded.

Can't recommend it enough. Managed to get work to pay for it too which was a bonus.

For a rack you would ideally have braze-ons (well, OK, they are usually not brazed on now) for a rack - so that you can screw it directly to the frame. If you don't have these, you could use p-clips (as I do) or there is also a tubus quick release bracket out there. Can email links if these are necessary.

For a rack I would recommend one with a fitting for a rear light (some don't have them and it can be a real hassle to mount a light which is actually visible if this is the case). I also like the racks with a "dog-leg" design - this is an extra strut which supports the pannier further back on the bike (so instead of 2 struts on each side, you have 3) - this helps to avoid a fairly empty pannier from sloshing about and striking the spokes. The Tourtec one looks fine to me. Bear in mind that if you buy one with hollow oversized tubes (10 mm), your pannier might not fit on it - so check!!!

I like a single pannier or a rack pack (the Altura expanding rack pack is good, although you wouldn't get a laptop in there). I personally never use a triple pannier and find that there is plenty of room in either the single pannier or rack pack. I take clothes etc each day, but I find this doesn't take up too much space - see what you like doing.

Try SJS cycles they sell deta panniers 14.5 ltr capacity,similar build to ortileb but much cheaper. I use one and a Tortec panier rack for commuting.

I've used a backpack (sticky, hate it), a pannier (space but heavy) and a rack bag (good but heavy since it needs a rack, as suggested by the name).

Each person is different, but the perfect solution for me is a Carradice Slim, fitted by an SQR block. Since I leave suit, shoes, etc at work, I can fit all I need, takes A4 documents, it's reasonably light, totally waterproof and has the bonus it keeps some of the wet and dirt off your back. Also, with a second SQR block I can swap it onto my mountain bike.

Forgot to mention if you spend over £50. you get an additional 10% off.