Fast enough isn't asking the right question. If you are downloading from youtube it doesn't matter if the speed isn't consistent, as you just wait for it to be loaded to watch it. With Skype and other real time apps, if the speed is inconsistent you'll set break up in the call which makes it unusable. So you might want to look into things like response, time, Ping times, etc. As its better with some ISP than others. Generally Eircom, BT etc are good. Wireless ones like IBB can be inconsistent. My NTL is a bit inconsistent but I think thats unusual.
In my opinion 1MB is fine for general use, even gaming and telephony if the reponse times are ok. Personally I wouldn't bother with anything other then unlimited as people have a habit of leaving the computer/web on, forgetting it and then comming back to it. So you don't want to be clock watching. You can leave
Shop around as you generally get a better a deal with a bundle that includes line rental, a phone call bundle and your internet as a all in one deal. Avoid paying Eircoms line rental at all costs. This link might be useful.
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