Do Not delete the log file.
Add more space and/or remove files that aren't necessary (old backups, logs, etc)
What error do you get when you try to connect? Logging in doesn't require log space, so shouldn't be a problem.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability