I assume you are talking about confirmation time not transaction time. Transaction time is commonly understood as the time it takes for the other party to know a transaction exists. Bitcoin does this in a matter of seconds, I doubt any alt is faster in that regard.

Confirmation time is something completly different. Its the time it takes for your transaction to be in a block. For bitcoin the average time for a new block is 10 minutes and IIRC the average time for the first confirmation is ~5-7 minutes. This varies of course and there are some alt coins out there that want to make you think their coin is better because their average time for the first block is e.g. 1 minute. Keep in mind though that less time between two blocks means also more work wasted, because it creates a higher chance for orphans. This will make the alt coin network less secure, because it would need more resources to offer the same level of security (to prevent a 51% attack). Besides that an alt coin is typically less secure because less people are invested into it and thus less overall hashing power is spent on the alt coins network.

To sum this up, yes you can lower the time between two blocks, but its a trade off with network security. For miners a higher time between blocks is preferable, because it lowers the risk of orphans and thus of wasted work (considering a PoW coin).