If budget is a concern, and tap tempo is not the biggest priority on your list, I would not hesitate to recommend the Digitech Digidelay. The analog delay sim on that is pretty good, the regular digital repeats are musical, it's a cheap, easy to use, set and forget pedal. However the tap tempo is not great - entails you holding the switch down for 3 or 4 seconds - and in any case most stompbox sized pedals with a tap tempo function only have the tap tempo reflect quarter notes and not dotted eights, when most players may need either one or the other depending on the song.
if you want to go all the way, my desert island delay would be the TC Electronics Nova Delay - and i have owned or extensively tried almost every popular delay on the market. Even as a delay newbie it's really not that complicated to use once you read the manual a couple times and play around with it. You'll figure it out after a couple days at most. It's very intuitive, actually - set it to Manual mode, and it's almost like what you see is what you get. There are up to scrollable 9 presets to save to. The display readout is amazing (shows delay time in milliseconds or converts to BPM, which is killer if you're playing to a set tempo), it's just slightly larger than a regular stompbox, and it runs fine off a 1 Spot or a PP2 output. Your repeats can be set anywhere from crisp to warm & fat, and you can throw in one of 3 flavours of modulation for your repeats. The tap tempo has a dedicated switch so you don't have to hold down the main switch to trigger that like most delay pedals require. You can also set tap tempo by holding the switch down and strumming the rhythm - a great feature. The repeats can be set to quarter notes, dotted eights, 8th note triplets and very cool hybrids of these which sound great in mono but superb in stereo. There's an interesting "Dynamic" feature which is quite genius - great for solos where you don't want the delay repeats clogging up your lines. Basically the delay effect is very slight when you are playing, and the volume of the repeats only come up when you stop playing.
the Nova is over your 300 budget, but you might be able to swing a used one on ebay for that price or slightly more. in any case, i reckon it's well worth saving an extra 100 for.
Sorry, but i've had the Boss DD2, DD3 and DD5 and I find these average at best - never liked the digital repeats much, and between the coveted DD2 and the Digidelay (on regular digital repeat mode) i'd pick the latter any day. The Line 6 DL4 is almost irrelevant next to new models like the DD20, Nova Delay and Eventide Timefactor, although the Echo Park is pretty ok (although i'd still pick the Digidelay between the two).
Good luck with getting one that suits your needs.
